Reciprocating Compressor Fault Detection Method and Device

Abstract

The present disclosure relates to a reciprocating compressor fault detection method and device. The reciprocating compressor fault detection device includes a key phase sensor, a stress detection component, an exhaust pressure detection component, and a control component. The key phase sensor is connected to the rotating component of the reciprocating compressor, the stress detection component is connected to the cylinder head of the reciprocating compressor, the exhaust pressure detection component is connected to the cylinder exhaust buffer tank of the reciprocating compressor, and the control component is connected to the key phase sensor, the stress detection component, and the exhaust pressure detection component. The method includes: determining the cylinder operation cycle of the reciprocating compressor according to the crankshaft phase angle, obtaining the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle, and determining whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operation cycles, thereby realizing reliable and timely liquid hammer fault detection.

Description

Technical Field

[0001] The present disclosure relates to the field of compressors, and in particular, to a reciprocating compressor fault detection method and device. Background Art

[0002] Reciprocating compressors have the characteristics of wide application range and high compression ratio, and are usually widely used as core equipment in fields such as petrochemical and refrigeration. However, reciprocating compressors have many vulnerable parts, many fault sources, and a relatively high failure rate, making it difficult for the unit to operate stably for a long time. Field experience has found that piston rod fracture is one of the most serious types of faults in reciprocating compressors, and may even lead to safety accidents such as explosions. Research shows that the liquid hammer factor is one of the main reasons for piston rod fracture. Thus, the liquid hammer problem of reciprocating compressors may directly cause safety accidents such as piston rod fracture. To prevent similar safety accidents, it is very important to avoid the liquid hammer problem of reciprocating compressors. In current actual operations, the detection of liquid hammer faults relies on manual judgment based on the noise in the cylinder, and the manual judgment method is not reliable enough and is prone to false detection or missed detection. Summary of the Invention

[0003] To solve the above problems, the present disclosure provides a reciprocating compressor fault detection method and device.

[0004] In a first aspect, the present disclosure provides a reciprocating compressor fault detection method, which is applied to a control component in a reciprocating compressor fault detection device. The reciprocating compressor fault detection device includes a key phase sensor, a stress detection component, an exhaust pressure detection component, and the control component. The key phase sensor is connected to the rotating component of the reciprocating compressor, the stress detection component is connected to the cylinder head of the reciprocating compressor, the exhaust pressure detection component is connected to the cylinder exhaust buffer tank of the reciprocating compressor, and the control component is connected to the key phase sensor, the stress detection component, and the exhaust pressure detection component. The method includes:

[0005] Obtain the crankshaft phase angle detected by the key phase sensor, and determine the cylinder operation cycle of the reciprocating compressor according to the crankshaft phase angle;

[0006] Obtain the maximum stress of the cylinder head and the exhaust buffer tank pressure within the cylinder operation cycle, where the exhaust buffer tank pressure is the maximum value of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the maximum stress of the cylinder head is the maximum value of the cylinder head stress obtained according to the strain value of the cylinder head detected by the stress detection component;

[0007] Determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the exhaust buffer tank pressure in two or more of the cylinder operation cycles.

[0008] Optionally, before periodically obtaining the maximum cylinder head stress and the exhaust buffer tank pressure for each cylinder operating cycle, the method further includes: determining the cylinder operating state of the reciprocating compressor according to the crankshaft phase angle; the obtaining of the maximum cylinder head stress and the exhaust buffer tank pressure for the cylinder operating cycle includes: obtaining the maximum cylinder head stress and the exhaust buffer tank pressure when the cylinder operating state is in the exhaust state during the cylinder operating cycle.

[0009] Optionally, the determining whether there is a liquid slugging fault in the reciprocating compressor according to the maximum cylinder head stress and the exhaust buffer tank pressure for two or more of the cylinder operating cycles includes: correcting the maximum cylinder head stress for this cycle according to the ratio of the exhaust buffer tank pressure in the previous cycle to the exhaust buffer tank pressure in this cycle, to obtain the corrected value of the maximum cylinder head stress for this cycle; determining that there is a liquid slugging fault in the reciprocating compressor when the first change rate of the corrected value of the maximum cylinder head stress for this cycle and the maximum cylinder head stress in the previous cycle is greater than or equal to the first preset change rate threshold.

[0010] Optionally, the reciprocating compressor fault detection device further includes an intake pressure detection component, which is connected to the cylinder intake buffer tank and the control component of the reciprocating compressor and is used to detect the cylinder intake pressure. Before determining whether there is a liquid slugging fault in the reciprocating compressor according to the maximum cylinder head stress and the exhaust buffer tank pressure for two or more of the cylinder operating cycles, the method further includes: obtaining the cylinder head intake stress and the cylinder intake pressure when the cylinder operating state is in the intake state during the cylinder operating cycle; obtaining the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the cylinder head intake stress, the cylinder intake pressure, and the maximum cylinder head stress; obtaining the cylinder head side exhaust pressure ratio of the calculated maximum exhaust pressure on the cylinder head side to the exhaust buffer tank pressure.

[0011] The determining whether there is a liquid slugging fault in the reciprocating compressor according to the maximum cylinder head stress and the exhaust buffer tank pressure for two or more of the cylinder operating cycles includes: determining that there is a liquid slugging fault in the reciprocating compressor when the second change rate of the cylinder head side exhaust pressure ratio in this cycle and the cylinder head side exhaust pressure ratio in the previous cycle is greater than or equal to the second preset change rate threshold.

[0012] Optionally, there are multiple cylinders, stress detection components, exhaust pressure detection components, and intake pressure detection components, where: the multiple stress detection components are respectively connected to the cylinder heads of the multiple cylinders one by one, the multiple exhaust pressure detection components are respectively connected to the cylinder exhaust buffer tanks of the multiple cylinders one by one, and the multiple intake pressure detection components are respectively connected to the cylinder intake buffer tanks of the multiple cylinders one by one; the control component is respectively connected to the multiple stress detection components, the multiple exhaust pressure detection components, and the multiple intake pressure detection components.

[0013] Optionally, the stress detection component includes multiple strain gauges. Any one of the multiple strain gauges is arranged at the center position of the outer surface of the cylinder head, and the remaining strain gauges are arranged on the outer surface of the cylinder head, and the distances between different strain gauges and the center position are different.

[0014] Optionally, determining the operating state of the cylinder of the reciprocating compressor according to the crankshaft phase angle includes: when the phase angle is in the first preset phase angle range, determining that the operating state of the cylinder is the suction state; when the phase angle is in the second preset phase angle range, determining that the operating state of the cylinder is the exhaust state.

[0015] In a second aspect, the present disclosure provides a reciprocating compressor fault detection device applied to a reciprocating compressor. The device includes a key phase sensor, a stress detection component, an exhaust pressure detection component, and a control component. The key phase sensor is connected to the rotating component of the reciprocating compressor, the stress detection component is connected to the cylinder head of the reciprocating compressor, the exhaust pressure detection component is connected to the cylinder exhaust buffer tank of the reciprocating compressor, and the control component is connected to the key phase sensor, the stress detection component, and the exhaust pressure detection component, where:

[0016] The key phase sensor is used to detect the crankshaft phase angle of the reciprocating compressor;

[0017] The stress detection component is used to detect the strain value of the cylinder head;

[0018] The exhaust pressure detection component is used to detect the cylinder exhaust pressure;

[0019] The control component is configured to obtain the crankshaft phase angle detected by the key-phase sensor, and determine the cylinder operation period of the reciprocating compressor according to the crankshaft phase angle; obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation period, where the pressure of the exhaust buffer tank is the maximum value of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the maximum stress of the cylinder head is the maximum value of the cylinder head stress obtained according to the strain value of the cylinder head detected by the stress detection component; determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more of the cylinder operation periods.

[0020] Optionally, the device further includes an intake pressure detection component, which is connected to the cylinder intake buffer tank and the control component of the reciprocating compressor, where: the intake pressure detection component is configured to detect the cylinder intake pressure; the control component is further configured to: determine the cylinder operation state of the reciprocating compressor according to the crankshaft phase angle; obtain the intake stress of the cylinder head and the cylinder intake pressure when the cylinder operation state is the intake state within the cylinder operation period, and the maximum stress of the cylinder head and the pressure of the exhaust buffer tank when the cylinder operation state is the exhaust state; obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the intake stress of the cylinder head, the cylinder intake pressure, and the maximum stress of the cylinder head; obtain the exhaust pressure ratio on the cylinder head side between the calculated maximum exhaust pressure on the cylinder head side and the pressure of the exhaust buffer tank; determine that there is a liquid hammer fault in the reciprocating compressor when the second change rate between the exhaust pressure ratio on the cylinder head side in this period and the exhaust pressure ratio on the cylinder head side in the previous period is greater than or equal to the second preset change rate threshold.

[0021] Optionally, there are multiple cylinders, stress detection components, exhaust pressure detection components, and intake pressure detection components, where: multiple stress detection components are respectively connected to the cylinder heads of multiple cylinders one by one, multiple exhaust pressure detection components are respectively connected to the cylinder exhaust buffer tanks of multiple cylinders one by one, and multiple intake pressure detection components are respectively connected to the cylinder intake buffer tanks of multiple cylinders one by one; the control component is respectively connected to the multiple stress detection components, the multiple exhaust pressure detection components, and the multiple intake pressure detection components.

[0022] Optionally, the stress detection component includes multiple strain gauges, and any one of the multiple strain gauges is arranged at the center position of the outer surface of the cylinder head, and the remaining strain gauges are arranged on the outer surface of the cylinder head, and the distances between different strain gauges and the center position are different.

[0023] By adopting the above technical solution, the cylinder operation cycle of the reciprocating compressor is determined according to the crankshaft phase angle, the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle are obtained, and whether there is a liquid hammer fault in the reciprocating compressor is determined according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operation cycles, thereby realizing reliable and timely detection of liquid hammer faults.

[0024] Other features and advantages of the present disclosure will be described in detail in the following specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification, and are used to explain the present disclosure together with the following specific implementation manners, but do not constitute a limitation to the present disclosure. In the accompanying drawings:

[0026] Figure 1 is a schematic structural diagram of a reciprocating compressor fault detection device provided by an embodiment of the present disclosure;

[0027] Figure 2 is a schematic structural diagram of another reciprocating compressor fault detection device provided by an embodiment of the present disclosure;

[0028] Figure 3 is a schematic diagram of the arrangement of a plurality of strain gauges on the cylinder head provided by an embodiment of the present disclosure;

[0029] Figure 4 is a schematic structural diagram of another reciprocating compressor fault detection device provided by an embodiment of the present disclosure;

[0030] Figure 5 is a flowchart of a reciprocating compressor fault detection method provided by an embodiment of the present disclosure;

[0031] Figure 6 is a flowchart of another reciprocating compressor fault detection method provided by an embodiment of the present disclosure;

[0032] Figure 7 is a schematic diagram of the change of the cylinder head stress with the crankshaft phase angle provided by an embodiment of the present disclosure;

[0033] Figure 8 is a schematic diagram of the change of the side pressure of the cylinder head with the crankshaft phase angle provided by an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following will describe in detail the specific implementation manners of the present disclosure with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0035] In the following description, terms such as "first" and "second" are only used for the purpose of distinguishing descriptions, and should not be construed as indicating or implying relative importance, nor as indicating or implying order.

[0036] First, the application scenarios of the present disclosure will be described. The present disclosure can be applied to the field of compressors, especially the liquid hammer fault detection of reciprocating compressors. A liquid hammer fault refers to the phenomenon that liquid enters the cylinder of a reciprocating compressor. Due to the incompressibility of the liquid, during the compression process of the piston of the reciprocating compressor, the piston suddenly changes from compressing gas to compressing incompressible liquid, resulting in abnormal impacts on components such as the piston rod and the valve disc of the air valve. Regarding the liquid hammer problem, the current related technologies mainly focus on two aspects: avoiding liquid from entering the compressor cylinder and draining the liquid in the cylinder, but there is no means to detect liquid hammer faults. In current actual operations, the detection of liquid hammer faults relies on manual judgment based on the noise in the cylinder, and manual judgment depends on personal experience. Most people have a very low judgment accuracy, and even those with rich personal experience will have a certain probability of false detection or missed detection.

[0037] To solve the above problems, the present disclosure provides a method and device for detecting faults of a reciprocating compressor. The cylinder operation cycle of the reciprocating compressor is determined according to the crankshaft phase angle, the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle are obtained, and whether there is a liquid hammer fault in the reciprocating compressor is determined based on the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operation cycles, thereby realizing reliable and timely detection of liquid hammer faults.

[0038] The following will describe the specific embodiments of the present disclosure in detail with reference to the accompanying drawings.

[0039] Figure 1 is a schematic structural diagram of a fault detection device provided by an embodiment of the present disclosure, Figure 1 The reciprocating compressor fault detection device is shown in. First, the working principle of the reciprocating compressor will be described:

[0040] A reciprocating compressor refers to a compressor that realizes the pressurization and transportation of gas by the reciprocating motion of a piston, a plunger or a diaphragm in a cylinder. As Figure 1 shown, a reciprocating compressor generally includes a cylinder, a piston, a rotating component, a cylinder intake buffer tank and a cylinder exhaust buffer tank, etc. The cylinder includes a cylinder head, a cylinder block, an intake valve and an exhaust valve, etc.

[0041] Among them, the rotating component includes a crankshaft, a flywheel and other rotating components, which drive the piston to reciprocate in the cylinder, that is, drive the piston to reciprocate between the side close to the cylinder head and the side far from the cylinder head.

[0042] During one operating cycle of a cylinder of a reciprocating compressor, the working process can be divided into four processes: expansion, suction, compression, and exhaust. The corresponding cylinder operating states are the expansion state, the suction state, the compression state, and the exhaust state. The following is a brief description of these four states on the cylinder head side:

[0043] Expansion state: When the piston moves from the side close to the cylinder head of the cylinder towards the side away from the cylinder head, the residual gas originally remaining on the cylinder head side continuously expands, and the gas pressure on the cylinder head side decreases.

[0044] Suction state: When the pressure on the cylinder head side drops slightly below the cylinder intake pressure in the cylinder intake buffer tank, the gas in the cylinder intake buffer tank pushes open the intake valve and enters the cylinder. As the piston moves towards the side away from the cylinder head, the gas continues to enter the cylinder until the piston moves to the other end (also known as the inner dead center) on the side away from the cylinder head. During the suction process, the pressure on the cylinder head side remains basically unchanged.

[0045] Compression state: When the piston reverses its direction and moves towards the cylinder head side, the volume on the cylinder head side gradually decreases, thus starting the process of compressing the gas. At this time, both the intake valve and the exhaust valve are in the closed state. Due to the reduction of the volume on the cylinder head side, the pressure on the cylinder head side continuously increases.

[0046] Exhaust state: As it moves towards the cylinder head side, when the pressure on the cylinder head side rises slightly above the gas pressure in the cylinder exhaust buffer tank, the gas in the cylinder pushes open the exhaust valve and enters the cylinder exhaust buffer tank, and is continuously discharged until the piston moves to the end (also known as the outer dead center) on the cylinder head side. Then, the piston starts to move towards the side away from the cylinder head again, repeating the above process.

[0047] In this way, the piston continuously reciprocates in the cylinder, enabling the cylinder to cyclically inhale and discharge gas. In this way, the cylinder goes through the above four states as one cylinder operating cycle.

[0048] As Figure 1 shown, the above-mentioned reciprocating compressor fault detection device 100 can be used to detect whether there is a liquid hammer fault in the reciprocating compressor. The reciprocating compressor fault detection device 100 may include: a key phase sensor 101, a stress detection component 102, an exhaust pressure detection component 103, and a control component 104. Among them, the key phase sensor 101 is connected to the rotating component of the reciprocating compressor, the stress detection component 102 is connected to the cylinder head of the reciprocating compressor, the exhaust pressure detection component 103 is connected to the cylinder exhaust buffer tank of the reciprocating compressor, and the control component 104 is connected to the key phase sensor 101, the stress detection component 102, and the exhaust pressure detection component 103, where:

[0049] The key phase sensor 101 is used to detect the crankshaft phase angle of the reciprocating compressor.

[0050] The stress detection component 102 is used to detect the strain value of the cylinder head.

[0051] The exhaust pressure detection component 103 is used to detect the cylinder exhaust pressure.

[0052] The control component 104 is used to obtain the crankshaft phase angle detected by the key phase sensor, and determine the cylinder operation cycle of the reciprocating compressor according to the crankshaft phase angle; obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle, where the pressure of the exhaust buffer tank is the maximum value of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the maximum stress of the cylinder head is the maximum value of the cylinder head stress obtained according to the strain value of the cylinder head detected by the stress detection component; determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operation cycles.

[0053] Figure 2 It is a schematic structural diagram of another reciprocating compressor fault detection device 100 provided by an embodiment of the present disclosure. As Figure 2 shown, the device further includes an intake pressure detection component 201, and the intake pressure detection component 201 is connected to the cylinder intake buffer tank and the control component of the reciprocating compressor, where:

[0054] The intake pressure detection component 201 is used to detect the cylinder intake pressure;

[0055] The control component 104 is further used to: periodically obtain the intake stress of the cylinder head and the cylinder intake pressure when the cylinder operation state is the intake state; determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head, the pressure of the exhaust buffer tank, the intake stress of the cylinder head, and the cylinder intake pressure in two or more cycles.

[0056] It should be noted that the specific manner in which the above control component performs operations will be described in detail in subsequent embodiments of the present disclosure regarding this method.

[0057] In some other embodiments of the present disclosure, the above control component may include a signal acquisition card and a controller. Through the signal acquisition card, the detection signals of the above key phase sensor, stress detection component, exhaust pressure detection component, and intake pressure detection component can be input to the controller, so as to complete the acquisition of the crankshaft phase angle detected by the key phase sensor, the acquisition of the cylinder head stress detected by the stress detection component, the acquisition of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the acquisition of the cylinder intake pressure detected by the intake pressure detection component. In this way, the signal transmission between the above sensors or detection components and the controller can be realized.

[0058] In addition, the above stress detection component may include a plurality of strain gauges. Figure 3is the arrangement of multiple strain gauges provided by the embodiments of the present disclosure on the cylinder head. As Figure 3 shown, any one of the multiple strain gauges arranged on the cylinder head is arranged at the central position of the outer surface of the cylinder head, and the remaining strain gauges are arranged on the outer surface of the cylinder head, and the distances between different strain gauges and the central position are different. In this way, the reliability of detection can be enhanced through multiple strain gauges.

[0059] Figure 4 is a schematic structural diagram of another reciprocating compressor fault detection device 100 provided by the embodiments of the present disclosure. As Figure 4 shown, the above-mentioned cylinder, stress detection component, exhaust pressure detection component, and intake pressure detection component can all be multiple, where:

[0060] The reciprocating compressor can have multiple cylinders, each cylinder has a cylinder head, a cylinder exhaust buffer tank, and a cylinder intake buffer tank. Multiple stress detection components are connected to the cylinder heads of multiple cylinders one by one, multiple exhaust pressure detection components are connected to the cylinder exhaust buffer tanks of multiple cylinders one by one, and multiple intake pressure detection components are connected to the cylinder intake buffer tanks of multiple cylinders one by one.

[0061] The control component can be connected to multiple stress detection components, multiple exhaust pressure detection components, and multiple intake pressure detection components.

[0062] In this way, for a reciprocating compressor with multiple cylinders, each cylinder can be detected, and any cylinder with a liquid hammer fault can be discovered in time.

[0063] Figure 5 is a schematic diagram of a reciprocating compressor fault detection method provided by the embodiments of the present disclosure. As Figure 5 shown, the execution subject of this method can be the control component in the above-mentioned Figure 1 shown reciprocating compressor fault detection device. This method can include:

[0064] S501. Obtain the crankshaft phase angle detected by the key phase sensor, and determine the cylinder operation cycle of the reciprocating compressor according to this crankshaft phase angle.

[0065] Among them, the cylinder operation cycle of the reciprocating compressor represents the cycle in which the volume of the cylinder body completes a change process through one reciprocating motion of the piston or diaphragm, that is, the cycle of completing the four processes of expansion, suction, compression, and exhaust.

[0066] The key phase sensor obtains the crankshaft phase angle of the reciprocating compressor by measuring the rotation of the rotating component. After the control component obtains this crankshaft phase angle, it can regard the process of one round of change of the crankshaft phase angle from the minimum value to the maximum value as an operating cycle of a cylinder of the reciprocating compressor. For example, if the crankshaft phase angle measured by the above key phase sensor is from 0 degrees to 360 degrees, then the process of the crankshaft phase angle from 0 degrees to 360 degrees can be regarded as an operating cycle of a cylinder of the reciprocating compressor.

[0067] S502. Obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operating cycle.

[0068] Among them, the maximum stress of the cylinder head is the maximum value of the cylinder head stress obtained according to the strain value of the cylinder head detected by the stress detection component. The pressure of the exhaust buffer tank is the pressure of the exhaust buffer tank of the cylinder detected by the exhaust pressure detection component. It should be noted that within one cylinder operating cycle, the gas pressure in the exhaust buffer tank is relatively stable. Therefore, the average value or the maximum value of the pressure detected by the exhaust pressure detection component within the cylinder operating cycle can be used as the pressure of the exhaust buffer tank, or the instantaneous pressure detected by the exhaust pressure detection component at any moment can also be selected as the pressure of the exhaust buffer tank.

[0069] The method of obtaining the cylinder head stress according to the strain value of the cylinder head detected by the stress detection component can be: obtaining the cylinder head stress according to the strain value of the cylinder head and the structural parameters of the cylinder head. Among them, the structural parameters of the cylinder head can include the Poisson's ratio and elastic modulus of the cylinder head material, and these structural parameters can be preset according to the actual material of the cylinder head. The stress detection component can detect the biaxial strain value of the cylinder head, that is, the radial strain value and the circumferential strain value. Then the stress of the cylinder head can be calculated according to the following formula:

[0070] ,

[0071] Among them, represents the stress of the cylinder head, represents the Poisson's ratio of the cylinder head material, represents the elastic modulus of the cylinder head material, represents the radial strain value, represents the circumferential strain value.

[0072] Optionally, the above stress detection component can include strain gauges, especially it can include biaxial dynamic strain gauges. The biaxial strain gauges can measure the strains in two mutually perpendicular directions at the same time, that is, they can detect the radial strain value and the circumferential strain value of the cylinder head, saving the number of strain gauges. In addition, compared with static strain gauges, dynamic strain gauges have a higher response frequency and can capture higher frequency stress changes. This can improve the accuracy of stress measurement and thus improve the accuracy of liquid hammer fault detection.

[0073] Optionally, the above strain gauges can be arranged at the central position of the outer surface of the cylinder head to obtain more accurate detection results.

[0074] Of course, the above stress detection assembly can include two ordinary strain gauges to respectively detect the radial strain value and the circumferential strain value of the cylinder head.

[0075] It should be noted that the method of measuring strain values by strain gauges is widely used and has characteristics such as high measurement accuracy and good dynamic response. Taking the resistance strain gauge as an example, its working principle is that the resistance metal wire in the strain gauge undergoes mechanical deformation under the stress action on the surface of the device, and the resistance also changes accordingly with the mechanical deformation. Specifically, when under tensile stress, the length of the resistance wire increases, the cross-sectional area decreases, and the resistance value increases. In practical applications, the above strain gauges can be connected to a bridge circuit. Among them, the bridge circuit can be divided into connection forms such as 1 / 4 bridge circuit, half-bridge circuit, and full-bridge circuit. Their basic principle is that when the resistance of the strain gauge changes, the voltage across the resistance wire of the strain gauge in the circuit also changes accordingly. In this way, the strain value on the surface of the device can be converted into a voltage value that can be directly monitored online, so as to obtain the strain value on the surface of the device. The technology of obtaining strain values through strain gauges above is well-known in the art. The present disclosure is also not limited to the use of other stress detection assemblies to obtain strain values.

[0076] S503. Determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operating cycles.

[0077] It should be noted that the above two or more cylinder operating cycles can be two adjacent front and back cycles, or two non-adjacent cycles, and the present disclosure does not limit this.

[0078] For example: It can be in units of months. Obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank every month, and compare the maximum stress of the cylinder head and the pressure of the exhaust buffer tank this month with those of last month, so as to determine whether there is a liquid hammer fault in the reciprocating compressor. Similarly, it can also be in units of weeks. Obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank every week, and compare the data of this week with that of last week, so as to determine whether there is a liquid hammer fault in the reciprocating compressor.

[0079] By adopting the above method, determine the cylinder operating cycle of the reciprocating compressor according to the crankshaft phase angle, obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank during the cylinder operating cycle, and determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operating cycles, thereby realizing reliable and timely detection of liquid hammer faults.

[0080] Further, according to the working principle of the reciprocating compressor, the maximum stress of the cylinder head and the pressure of the exhaust buffer tank during the cylinder operation cycle generally occur when the cylinder is in the exhaust state. In this way, the cylinder operation state of the reciprocating compressor can also be determined according to the crankshaft phase angle, and the maximum stress of the cylinder head and the pressure of the exhaust buffer tank when the cylinder operation state is in the exhaust state during the cylinder operation cycle can be obtained. Then, it can be determined whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more cylinder operation cycles. In this way, the reliability and detection efficiency of liquid hammer fault detection can be further improved.

[0081] Among them, the cylinder operation state of the reciprocating compressor is related to the above-mentioned crankshaft phase angle. When the crankshaft phase angle is in the first preset phase angle interval, it can be determined that the cylinder is in the suction state; when the crankshaft phase angle is in the second preset phase angle interval, it can be determined that the cylinder is in the exhaust state.

[0082] Exemplarily, the crankshaft phase angle measured by the above-mentioned key phase sensor can be defined as 0 degrees to 360 degrees, where 0 degrees to 180 degrees include the expansion and suction states, and 180 degrees to 360 degrees include the compression and exhaust states. In this way, the above-mentioned first preset phase angle interval can be any interval between 0 degrees and 180 degrees, for example, it can be 90 degrees to 180 degrees, or it can be 120 degrees to 180 degrees; similarly, the above-mentioned second phase angle interval can be any interval between 180 degrees and 360 degrees, for example, it can be 270 degrees to 360 degrees, or it can be 300 degrees to 360 degrees.

[0083] When it is determined that the cylinder operation state is in the exhaust state according to the above-mentioned crankshaft phase angle, the stress of the cylinder head and the exhaust pressure during the entire exhaust state are obtained in real time, and the maximum values among them are respectively taken as the maximum stress of the cylinder head and the pressure of the exhaust buffer tank.

[0084] Exemplarily, if the above-mentioned second preset phase angle interval is 180 degrees to 360 degrees, that is, the preset crankshaft phase angle from 180 degrees to 360 degrees is the exhaust state, then the maximum value of the stress of the cylinder head and the maximum value of the cylinder exhaust pressure between the crankshaft phase angles of 180 degrees and 360 degrees can be obtained as the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in the exhaust state respectively.

[0085] In some other embodiments of the present disclosure, the above-mentioned step S503 can also determine whether there is a liquid hammer fault in the reciprocating compressor in the following manner:

[0086] First, according to the ratio of the pressure of the exhaust buffer tank in the previous cycle to the pressure of the exhaust buffer tank in this cycle, the maximum stress of the cylinder head in this cycle is corrected to obtain the corrected value of the maximum stress of the cylinder head in this cycle.

[0087] Due to changes in the external environment, the exhaust pressures in different cycles will vary. To more accurately detect liquid hammer faults, the maximum stress of the cylinder head in this cycle can be corrected according to the following formula to obtain the corrected value of the maximum stress of the cylinder head in this cycle:

[0088] ,

[0089] wherein, is the corrected value of the maximum stress of the cylinder head in this cycle, is the maximum stress of the cylinder head in this cycle, is the pressure of the exhaust buffer tank in the previous cycle, is the pressure of the exhaust buffer tank in this cycle.

[0090] Secondly, when the first change rate between the corrected value of the maximum stress of the cylinder head in this cycle and the maximum stress of the cylinder head in the previous cycle is greater than or equal to the first preset change rate threshold, it is determined that the reciprocating compressor has a liquid hammer fault.

[0091] The first change rate can be calculated using the following formula:

[0092] ,

[0093] wherein, is the first change rate, is the corrected value of the maximum stress of the cylinder head in this cycle, is the maximum stress of the cylinder head in the previous cycle.

[0094] Exemplarily, the above first preset change rate threshold can be any value greater than 110%, such as 120% or 200%. Then, when the above first change rate is greater than or equal to the first preset change rate threshold, it can be determined that the reciprocating compressor has a liquid hammer fault.

[0095] It should be noted that this method gives a method for detection using the change rate. Similarly, the change amount can also be used for detection. The method of using the change amount for detection is basically the same as the method of using the change rate, and it should be considered to belong to the same technical solution as the above detection using the change rate, which will not be elaborated here.

[0096] In addition, in this embodiment, the above two formulas can also be combined through mathematical operations into the following formula to directly calculate the first preset change rate:

[0097] .

[0098] wherein, is the first change rate, is the pressure of the exhaust buffer tank in the previous cycle, is the pressure of the exhaust buffer tank for this cycle, is the maximum stress of the cylinder head for this cycle, is the maximum stress of the cylinder head for the previous cycle.

[0099] It should also be noted that the above previous cycle can be the previous cycle adjacent to this cycle, or any cycle before this cycle that is not adjacent. For example: it can be in units of months, obtaining the maximum stress of the cylinder head and the pressure of the exhaust buffer tank every month, taking the maximum stress of the cylinder head and the pressure of the exhaust buffer tank this month as the maximum stress of the cylinder head and the pressure of the exhaust buffer tank for the above-mentioned this cycle, and taking the maximum stress of the cylinder head and the pressure of the exhaust buffer tank last month as the maximum stress of the cylinder head and the pressure of the exhaust buffer tank for the above-mentioned previous cycle, so as to determine whether there is a liquid hammer fault in the reciprocating compressor according to the above method.

[0100] In this way, even if the exhaust pressure in different cycles changes due to changes in the external environment, the maximum stress of the cylinder head can be corrected by the detected exhaust pressure, and whether there is a liquid hammer fault in the reciprocating compressor can be determined according to the change rate of the maximum stress of the cylinder head in the previous and current two cycles, which can increase the accuracy and timeliness of liquid hammer fault detection.

[0101] Figure 6 is a schematic diagram of a method for detecting faults in a reciprocating compressor provided by an embodiment of the present disclosure. As Figure 6 shown, the execution subject of this method can be the control component in the above-mentioned Figure 2 shown fault detection device. The fault detection device may further include an intake pressure detection component as shown in Figure 2 shown. The intake pressure detection component is connected to the cylinder intake buffer tank and the control component of the reciprocating compressor for detecting the cylinder intake pressure. This method may include:

[0102] S601. Obtain the crankshaft phase angle detected by the key phase sensor, and determine the cylinder operation cycle and cylinder operation state of the reciprocating compressor according to this crankshaft phase angle.

[0103] S602. Obtain the intake stress of the cylinder head and the cylinder intake pressure when the cylinder operation state is the intake state within the cylinder operation cycle, and obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank when the cylinder operation state is the exhaust state within the cylinder operation cycle.

[0104] In this step, one cycle includes a complete reciprocating operation cycle in which the cylinder operating states are expansion state, suction state, compression state, and exhaust state. In each cycle, when the cylinder operating state is determined to be the suction state according to the above-mentioned crankshaft phase angle, the suction stress of the cylinder head and the intake pressure of the cylinder are obtained. The suction stress of the cylinder head can be obtained according to the strain value of the cylinder head detected by the stress detection component, and the intake pressure of the cylinder can be obtained according to the detection result of the intake pressure detection component.

[0105] It should be noted that since the pressure and stress in the suction state are basically stable, in the suction state, the intake pressure value at any moment can be used as the intake pressure of the cylinder, and the stress value at any moment can be used as the suction stress of the cylinder head. Of course, the average value or maximum value of the intake pressure values detected during the entire suction state can also be used as the intake pressure of the cylinder, and the average value or maximum value of the stress values detected during the entire suction state can be used as the suction stress of the cylinder head.

[0106] Similarly, in each cycle, when the cylinder operating state is determined to be the exhaust state according to the above-mentioned crankshaft phase angle, the stress of the cylinder head and the exhaust pressure of the cylinder during the entire exhaust state are obtained in real time, and the maximum values thereof are respectively taken as the maximum stress of the cylinder head and the pressure of the exhaust buffer tank. The exhaust pressure of the cylinder can be obtained according to the detection result of the exhaust pressure detection component.

[0107] Exemplarily, if the preset crankshaft phase angle from 120 degrees to 180 degrees is the suction state, the suction stress of the cylinder head and the intake pressure of the cylinder between the crankshaft phase angles of 120 degrees and 180 degrees are obtained; if the preset crankshaft phase angle from 180 degrees to 360 degrees is the exhaust state, the maximum stress of the cylinder head and the pressure of the exhaust buffer tank between the crankshaft phase angles of 180 degrees and 360 degrees are obtained.

[0108] S603. Obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the suction stress of the cylinder head, the intake pressure of the cylinder, and the maximum stress of the cylinder head.

[0109] Among them, the calculation steps for obtaining the calculated maximum exhaust pressure on the cylinder head side in the exhaust state can also be divided into the following two steps:

[0110] First, according to the suction stress of the cylinder head and the intake pressure of the cylinder obtained when the cylinder operating state is the suction state, and the structural parameters of the cylinder, a correction coefficient is obtained. The specific formula can be:

[0111] ,

[0112] Among them, represents the correction coefficient of this cycle, represents the intake pressure of the cylinder in this cycle, R represents the cylinder radius, represents the Poisson's ratio of the cylinder head material, and t represents the central thickness of the cylinder head. represents the intake stress of the cylinder head in this cycle.

[0113] Then, based on this correction coefficient, the maximum stress of the cylinder head in the exhaust state of the same cylinder operation cycle, and the structural parameters of the cylinder, obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state. The specific formula can be:

[0114] ,

[0115] where, represents the calculated maximum exhaust pressure on the cylinder head side in this cycle, represents the correction coefficient in this cycle, R represents the radius of the cylinder, represents the Poisson's ratio of the cylinder head material, and t represents the central thickness of the cylinder head. represents the maximum stress of the cylinder head in this cycle.

[0116] It should be noted that the above structural parameters of the cylinder include: the radius of the cylinder, the Poisson's ratio of the cylinder head material, and the central thickness of the cylinder head, which can all be parameter values preset according to the cylinder structure.

[0117] S604. Obtain the exhaust pressure ratio of the cylinder head side between the calculated maximum exhaust pressure on the cylinder head side in this cycle and the pressure of the exhaust buffer tank.

[0118] ,

[0119] where, represents the exhaust pressure ratio of the cylinder head side in this cycle, represents the calculated maximum exhaust pressure on the cylinder head side in this cycle, represents the pressure of the exhaust buffer tank in this cycle.

[0120] S605. When the second change rate of the exhaust pressure ratio of the cylinder head side in this cycle and the exhaust pressure ratio of the cylinder head side in the previous cycle is greater than or equal to the second preset change rate threshold, determine that there is a liquid hammer fault in the reciprocating compressor.

[0121] In this step, the following formula can be used to calculate the second change rate:

[0122] ,

[0123] where, represents the second change rate, represents the exhaust pressure ratio of the cylinder head side in this cycle, represents the exhaust pressure ratio of the cylinder head side in the previous cycle.

[0124] Among them, the second preset change rate threshold may be equal to or different from the first change rate threshold. For example, the second preset change rate threshold may be any value greater than 110%, such as 120% or 200%. In this way, when the above second change rate is greater than or equal to 120%, it is determined that the reciprocating compressor has a liquid hammer fault.

[0125] In this way, according to the cylinder head suction stress and the cylinder intake pressure when the cylinder operating state is the suction state, and the maximum stress of the cylinder head and the exhaust buffer tank pressure when the cylinder operating state is the exhaust state, within two or more cylinder operating cycles, the second change rate of the exhaust pressure ratio on the cylinder head side is obtained. When the second change rate is greater than or equal to the second preset change rate threshold, it is determined that the reciprocating compressor has a liquid hammer fault, realizing a more reliable liquid hammer fault detection.

[0126] It should be noted that according to the test data, the relationship between the cylinder head stress, the pressure on the cylinder head side and the crankshaft phase angle can be obtained. For example, Figure 7 is a schematic diagram showing the change of the cylinder head stress with the crankshaft phase angle provided by an embodiment of the present disclosure; Figure 8 is a schematic diagram showing the change of the pressure on the cylinder head side with the crankshaft phase angle provided by an embodiment of the present disclosure.

[0127] According to Figure 7 and Figure 8 shown, the crankshaft phase angle measured by the key phase sensor is defined as 0 degrees to 360 degrees, where 0 degrees to 180 degrees include the expansion and suction states, and 180 degrees to 360 degrees include the compression and exhaust states. When a liquid hammer fault occurs, the maximum values of the cylinder head stress and the pressure on the cylinder head side will change greatly. Therefore, the change of the maximum stress of the cylinder head or the maximum exhaust pressure calculated from the pressure on the cylinder head side in two or more cycles can be used to detect whether the reciprocating compressor has a liquid hammer fault. Since the exhaust pressure in different cycles may be different, in the above embodiment, the maximum stress of the cylinder head or the maximum exhaust pressure calculated from the pressure on the cylinder head side is corrected based on the exhaust buffer tank pressure, and then the change rate is detected to further improve the reliability of the liquid hammer fault detection.

[0128] Furthermore, the change rates of the exhaust pressure ratio on the cylinder head side and the maximum stress of the cylinder head in the above two or more cycles can also be used simultaneously to detect whether the reciprocating compressor has a liquid hammer fault. It can be determined that the reciprocating compressor has a liquid hammer fault when the change rate of any one of the exhaust pressure ratio on the cylinder head side and the maximum stress of the cylinder head is greater than or equal to the first preset change rate threshold; it can also be determined that the reciprocating compressor has a liquid hammer fault when the change rates of the exhaust pressure ratio on the cylinder head side and the maximum stress of the cylinder head are both greater than or equal to the first preset change rate threshold. In this way, the reliability of the liquid hammer fault detection can be further improved.

[0129] In some other embodiments of the present disclosure, the above control component may include a signal acquisition card and a controller. The signal acquisition card can convert the detection signals of the above key phase sensor, stress detection component, exhaust pressure detection component, and intake pressure detection component into digital signals and input them to the controller, thereby completing the acquisition of the crankshaft phase angle detected by the key phase sensor, the acquisition of the cylinder head stress detected by the stress detection component, the acquisition of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the acquisition of the cylinder intake pressure detected by the intake pressure detection component. In this way, the signal transmission between the above sensors or detection components and the controller can be realized.

[0130] In addition, the above stress detection component may include a plurality of strain gauges. Any one of the plurality of strain gauges is arranged at the central position of the outer surface of the cylinder head, and the remaining strain gauges are arranged on the outer surface of the cylinder head, and the distances between different strain gauges and the central position are different. In this way, the reliability of detection can be enhanced by the plurality of strain gauges.

[0131] Furthermore, the above cylinders, stress detection components, exhaust pressure detection components, and intake pressure detection components are all multiple, where:

[0132] The reciprocating compressor has a plurality of cylinders, each cylinder has a cylinder head, a cylinder exhaust buffer tank, and a cylinder intake buffer tank. The plurality of stress detection components are connected to the cylinder heads of the plurality of cylinders one by one, the plurality of exhaust pressure detection components are connected to the cylinder exhaust buffer tanks of the plurality of cylinders one by one, and the plurality of intake pressure detection components are connected to the cylinder intake buffer tanks of the plurality of cylinders one by one.

[0133] The control component can be connected to the plurality of stress detection components, the plurality of exhaust pressure detection components, and the plurality of intake pressure detection components.

[0134] In this way, for a reciprocating compressor with a plurality of cylinders, each cylinder can be detected, and any cylinder with a liquid hammer fault can be detected in time.

[0135] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0136] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure does not separately describe various possible combination methods.

[0137] In addition, any combination can be made among various different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A reciprocating compressor fault detection method, characterized in that, A control component applied to a reciprocating compressor fault detection device. The reciprocating compressor fault detection device includes a key phase sensor, a stress detection component, an exhaust pressure detection component, and the control component. The key phase sensor is connected to a rotating component of the reciprocating compressor. The stress detection component is connected to a cylinder head of the reciprocating compressor. The exhaust pressure detection component is connected to a cylinder exhaust buffer tank of the reciprocating compressor. The control component is connected to the key phase sensor, the stress detection component, and the exhaust pressure detection component. The method includes: Obtain the crankshaft phase angle detected by the key phase sensor, and determine the cylinder operation cycle of the reciprocating compressor according to the crankshaft phase angle; Obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle. Among them, the pressure of the exhaust buffer tank is the maximum value of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the maximum stress of the cylinder head is the maximum value of the cylinder head stress obtained according to the strain value of the cylinder head detected by the stress detection component; Determine whether the reciprocating compressor has a liquid slugging fault according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more of the cylinder operation cycles; The determining whether the reciprocating compressor has a liquid slugging fault according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more of the cylinder operation cycles includes: According to the ratio of the pressure of the exhaust buffer tank in the previous cycle to the pressure of the exhaust buffer tank in the current cycle, correct the maximum stress of the cylinder head in the current cycle to obtain the corrected value of the maximum stress of the cylinder head in the current cycle; When the first change rate between the corrected value of the maximum stress of the cylinder head in the current cycle and the maximum stress of the cylinder head in the previous cycle is greater than or equal to the first preset change rate threshold, determine that the reciprocating compressor has a liquid slugging fault; The corrected value of the maximum stress of the cylinder head in the current cycle is determined by the following formula: , where is the maximum stress correction value of the cylinder head in this cycle, is the maximum stress of the cylinder head in this cycle, is the pressure of the exhaust buffer tank in the previous cycle, is the pressure of the exhaust buffer tank in this cycle; The first change rate is determined by the following formula: , where is the first change rate, is the maximum stress correction value of the cylinder head in this cycle, is the maximum stress of the cylinder head in the previous cycle.

2. The method according to claim 1, wherein Before periodically obtaining the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in each cylinder operation cycle, the method further includes: Determine the cylinder operation state of the reciprocating compressor according to the crankshaft phase angle; The obtaining the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle includes: Obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank when the cylinder operation state is the exhaust state within the cylinder operation cycle.

3. The method according to claim 2, characterized in that, The reciprocating compressor fault detection device further includes an intake pressure detection component. The intake pressure detection component is connected to a cylinder intake buffer tank and the control component of the reciprocating compressor for detecting the cylinder intake pressure. Before determining whether the reciprocating compressor has a liquid slugging fault according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more of the cylinder operation cycles, the method further includes: Obtain the intake stress of the cylinder head and the cylinder intake pressure when the cylinder operation state is the intake state within the cylinder operation cycle; According to the intake stress of the cylinder head, the cylinder intake pressure, and the maximum stress of the cylinder head, obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state; Obtain the exhaust pressure ratio on the cylinder head side by calculating the maximum exhaust pressure on the cylinder head side and the pressure of the exhaust buffer tank; Determining whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more operating cycles of the cylinder includes: When the second change rate of the exhaust pressure ratio on the cylinder head side in this cycle and the exhaust pressure ratio on the cylinder head side in the previous cycle is greater than or equal to the second preset change rate threshold, it is determined that there is a liquid hammer fault in the reciprocating compressor; Obtaining the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the suction stress of the cylinder head, the intake pressure of the cylinder, and the maximum stress of the cylinder head includes: Obtain a correction coefficient according to the suction stress of the cylinder head, the intake pressure of the cylinder, and the structural parameters of the cylinder; Obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the correction coefficient, the maximum stress of the cylinder head, and the structural parameters of the cylinder; The structural parameters of the cylinder include the radius of the cylinder, the Poisson's ratio of the cylinder head material, and the central thickness of the cylinder head. The correction coefficient is obtained through the following formula: , where is the correction coefficient for this cycle, is the intake air pressure of the cylinder for this cycle, is the radius of the cylinder, is the Poisson's ratio of the cylinder head material, is the central thickness of the cylinder head, is the intake stress of the cylinder head for this cycle; The calculated maximum exhaust pressure on the cylinder head side in the exhaust state is obtained through the following formula: , where is the calculated maximum exhaust pressure on the cylinder head side for this cycle, is the correction factor for this cycle, is the radius of the cylinder, is the Poisson's ratio of the cylinder head material, is the central thickness of the cylinder head, is the maximum stress of the cylinder head for this cycle; The exhaust pressure ratio on the cylinder head side is obtained through the following formula: , where is the exhaust pressure ratio on the cylinder head side for this cycle, is the calculated maximum exhaust pressure on the cylinder head side for this cycle, is the pressure of the exhaust buffer tank for this cycle.

4. The method according to claim 3, wherein There are multiple cylinders, stress detection components, exhaust pressure detection components, and intake pressure detection components, where: Multiple stress detection components are connected to the cylinder heads of multiple cylinders one by one, multiple exhaust pressure detection components are connected to the cylinder exhaust buffer tanks of multiple cylinders one by one, and multiple intake pressure detection components are connected to the cylinder intake buffer tanks of multiple cylinders one by one; The control component is respectively connected to the multiple stress detection components, the multiple exhaust pressure detection components, and the multiple intake pressure detection components.

5. The method according to any one of claims 1 to 4, characterized in that The stress detection component includes multiple strain gauges. Any one of the multiple strain gauges is arranged at the center position of the outer surface of the cylinder head, and the remaining strain gauges are arranged on the outer surface of the cylinder head, and the distances between different strain gauges and the center position are different.

6. The method according to claim 2, characterized in that, Determining the operating state of the cylinder of the reciprocating compressor according to the crankshaft phase angle includes: When the crankshaft phase angle is in the first preset phase angle interval, determine that the cylinder operating state is the suction state; When the crankshaft phase angle is in the second preset phase angle interval, determine that the cylinder operating state is the exhaust state.

7. A reciprocating compressor fault detection device, characterized in that, Applied to a reciprocating compressor, the device includes a key phase sensor, a stress detection component, an exhaust pressure detection component, and a control component. The key phase sensor is connected to the rotating component of the reciprocating compressor, the stress detection component is connected to the cylinder head of the reciprocating compressor, the exhaust pressure detection component is connected to the cylinder exhaust buffer tank of the reciprocating compressor, and the control component is connected to the key phase sensor, the stress detection component, and the exhaust pressure detection component, where: The key phase sensor is used to detect the crankshaft phase angle of the reciprocating compressor; The stress detection component is used to detect the strain value of the cylinder head; The exhaust pressure detection component is used to detect the cylinder exhaust pressure; The control component is used to obtain the crankshaft phase angle detected by the key phase sensor, and determine the cylinder operation cycle of the reciprocating compressor according to the crankshaft phase angle; obtain the maximum stress of the cylinder head and the pressure of the exhaust buffer tank within the cylinder operation cycle, where the pressure of the exhaust buffer tank is the maximum value of the cylinder exhaust pressure detected by the exhaust pressure detection component, and the maximum stress of the cylinder head is the maximum value of the cylinder head stress obtained according to the strain value of the cylinder head detected by the stress detection component; determine whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more of the cylinder operation cycles; Determining whether there is a liquid hammer fault in the reciprocating compressor according to the maximum stress of the cylinder head and the pressure of the exhaust buffer tank in two or more of the cylinder operation cycles includes: According to the ratio of the pressure of the exhaust buffer tank in the previous cycle to the pressure of the exhaust buffer tank in this cycle, correct the maximum stress of the cylinder head in this cycle to obtain the corrected value of the maximum stress of the cylinder head in this cycle; When the first change rate between the corrected value of the maximum stress of the cylinder head in this cycle and the maximum stress of the cylinder head in the previous cycle is greater than or equal to the first preset change rate threshold, it is determined that there is a liquid hammer fault in the reciprocating compressor; The corrected value of the maximum stress of the cylinder head in this cycle is determined by the following formula: , where is the maximum stress correction value of the cylinder head in this cycle, is the maximum stress of the cylinder head in this cycle, is the pressure of the exhaust buffer tank in the previous cycle, is the pressure of the exhaust buffer tank in this cycle; The first change rate is determined by the following formula: , where is the first change rate, is the maximum stress correction value of the cylinder head in this cycle, is the maximum stress of the cylinder head in the previous cycle.

8. The device according to claim 7, wherein The device further includes an intake pressure detection component, and the intake pressure detection component is connected to the cylinder intake buffer tank and the control component of the reciprocating compressor, where: The intake pressure detection component is used to detect the cylinder intake pressure; The control component is further used to: determine the cylinder operation state of the reciprocating compressor according to the crankshaft phase angle; obtain the intake stress of the cylinder head and the cylinder intake pressure when the cylinder operation state is the intake state within the cylinder operation cycle, and the maximum stress of the cylinder head and the pressure of the exhaust buffer tank when the cylinder operation state is the exhaust state; obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the intake stress of the cylinder head, the cylinder intake pressure and the maximum stress of the cylinder head; obtain the exhaust pressure ratio on the cylinder head side between the calculated maximum exhaust pressure on the cylinder head side and the pressure of the exhaust buffer tank; when the second change rate between the exhaust pressure ratio on the cylinder head side in this cycle and the exhaust pressure ratio on the cylinder head side in the previous cycle is greater than or equal to the second preset change rate threshold, it is determined that there is a liquid hammer fault in the reciprocating compressor; Obtaining the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the intake stress of the cylinder head, the cylinder intake pressure and the maximum stress of the cylinder head includes: Obtain a correction coefficient according to the intake stress of the cylinder head, the cylinder intake pressure, and the structural parameters of the cylinder; Obtain the calculated maximum exhaust pressure on the cylinder head side in the exhaust state according to the correction coefficient, the maximum stress of the cylinder head, and the structural parameters of the cylinder; The structural parameters of the cylinder include the radius of the cylinder, the Poisson's ratio of the cylinder head material, and the central thickness of the cylinder head. The correction coefficient is obtained by the following formula: , where is the correction coefficient for this cycle, is the intake air pressure of the cylinder for this cycle, is the radius of the cylinder, is the Poisson's ratio of the cylinder head material, is the central thickness of the cylinder head, is the intake stress of the cylinder head for this cycle; The maximum exhaust pressure on the cylinder head side in the exhaust state is obtained by the following formula: , where is the calculated maximum exhaust pressure on the cylinder head side for this cycle, is the correction factor for this cycle, is the radius of the cylinder, is the Poisson's ratio of the cylinder head material, is the central thickness of the cylinder head, is the maximum stress of the cylinder head for this cycle; The exhaust pressure ratio on the cylinder head side is obtained by the following formula: , where is the exhaust pressure ratio on the cylinder head side in this cycle, is the calculated maximum exhaust pressure on the cylinder head side in this cycle, is the pressure of the exhaust buffer tank in this cycle.

Images