Fault detection method and system for centrifugal machine

Abstract

The invention discloses a fault detection method and system for a centrifugal machine, and the method comprises the steps: recording a load monitoring value A0 of a transmission device when the centrifugal machine is in a normal operation state when the feeding flow of a feeding device is zero, namely the load monitoring value during no-load; in the actual production stage, the feeding flow S of the feeding device and the load monitoring value A of the transmission device are detected in real time; if A is smaller than or equal to A0 and S is larger than 0, the transmission device of the centrifugal machine breaks down, and the feeding device and the transmission device stop working. According to the method, the centrifugal machine in the working stage is detected, the load monitoring value and the feeding flow of the transmission device serve as entry points and are combined for judgment, and when the transmission device of the existing centrifugal machine breaks down, the failure can be found quickly and withdrawn from the production operation stage in time.

Description

Technical Field

[0001] The invention belongs to the technical field of centrifuge equipment, and in particular relates to a fault detection method and system for a centrifuge. Background Art

[0002] Horizontal screw centrifuge (hereinafter referred to as centrifuge) has been widely used in all walks of life. The stability and reliability of centrifuge operation are increasingly valued. The load protection measures of the centrifuge are the key to ensure the normal operation of the centrifuge, and the methods or means are becoming more and more abundant.

[0003] Currently, the load protections for centrifuges mainly include: current protection and torque protection.

[0004] Current protection monitors the working current of the motor that drives the centrifuge, or the working current of the frequency converter that controls the motor. When the motor reaches the rated allowable value, the control device can provide interlocking protection for the centrifuge.

[0005] Torque protection is to monitor the working torque of the centrifuge transmission shaft system (mainly the differential). When the torque reaches the rated allowable value, the control device can provide interlocking protection for the centrifuge.

[0006] The above current protection and torque protection can be used separately or simultaneously.

[0007] These measures have played a good protective role in the stable operation of the centrifuge, but there are some problems, such as: current protection, when the working current of the centrifuge (such as: motor current) reaches the set allowable value (overcurrent), the interlocking protection will be triggered. When the transmission device fails, the motor working current is very low (similar to the motor running at no load), and the interlocking protection will not be triggered. Torque protection, likewise, will only be triggered when the rated allowable value is reached. If the allowable value of current or torque is set too low, the centrifuge will be forced to fail to start and run normally.

[0008] When the transmission system of the centrifuge fails or fails, if it is not discovered and effectively protected in time, the materials entering the centrifuge will not be separated and discharged after the centrifuge is put into production, causing blockage inside the centrifuge and even damage to the centrifuge components, bringing serious consequences to production and safety. Summary of the invention

[0009] In order to solve the above technical problems, the present invention proposes a fault detection method and system for a centrifuge.

[0010] In order to achieve the above object, the technical solution of the present invention is as follows:

[0011] In one aspect, the present invention discloses a fault detection method for a centrifuge, comprising:

[0012] Step S1: when the feed flow rate of the feed device is zero, record the load monitoring value A0 of the transmission device of the centrifuge under normal operating conditions;

[0013] Step S3: In the actual production stage, the feed flow rate S of the feed device and the load monitoring value A of the transmission device are detected in real time;

[0014] If A≤A0 and S>0, the transmission device of the centrifuge fails, and the feeding device and the transmission device stop operating.

[0015] On the basis of the above technical solution, the following improvements can be made:

[0016] As a preferred solution, step S1 is further as follows:

[0017] Record the load monitoring value As of the transmission device when the centrifuge is started;

[0018] When the feed flow rate of the feed device is zero, record the load monitoring value A0 of the transmission device of the centrifuge under normal operating conditions.

[0019] As a preferred solution, step S3 is further as follows:

[0020] During the startup phase, the load monitoring value A of the transmission device is detected in real time;

[0021] If A≤a*As, or A fluctuates greatly, the centrifuge fails, and the feeding device and transmission device stop working;

[0022] Where: a is the preset parameter;

[0023] In the actual production stage, the feed flow S of the feed device and the load monitoring value A of the transmission device are detected in real time;

[0024] If A≤A0 and S>0, the transmission device of the centrifuge fails, and the feeding device and the transmission device stop operating.

[0025] As a preferred solution, between step S1 and step S3, the following is further included:

[0026] Step S2: The centrifuge is simulated under each fault state of the transmission device, and the relationship between the feed flow rate S and the load monitoring value A is recorded. Based on the relationship between the feed flow rate S and the load monitoring value A under different faults, a fault type determination model is trained. The fault type determination model is used to determine the corresponding fault type according to the real-time feed flow rate S and the load monitoring value A.

[0027] As a preferred solution, step S2 includes:

[0028] Step S2.1: Classify the fault types of the transmission device into N types;

[0029] Step S2.2: Divide the feed flow rate into M types according to the minimum threshold value Smin to the maximum threshold value Smax;

[0030] Step S2.3: When the centrifuge is in normal operation and the feed flow rate is stable at any type, any type of fault of the transmission device is simulated to record the load monitoring value;

[0031] Step S2.4: Repeat step S2.3 until all M feed flow rates are simulated;

[0032] Step S2.5: Repeat steps S2.3 to S2.4 until all N types of faults are simulated;

[0033] Step S2.6: fuzzify the precise values ​​of the M types of feed flow rates to obtain a fuzzy set;

[0034] Step S2.7: Establish a simulation database, in which the fuzzy set under each fault type and its corresponding load detection value are stored;

[0035] Step S2.8: Divide the data in the simulation database into a training set and a test set;

[0036] Step S2.9: Establish a fault type determination model;

[0037] Step S2.10: Use the training set to train the fault type determination model, and then use the test set to test and verify it.

[0038] As a preferred solution, when step S3 detects that the transmission device of the centrifuge fails, the feeding device and the transmission device stop operating, and step S4 is further executed. Step S4 is used to determine the fault type of the transmission device using a fault type determination model.

[0039] As a preferred solution, step S4 includes:

[0040] Step S4.1: Record the real-time feed flow rate S and the real-time load monitoring value A when the transmission device fails;

[0041] Step S4.2: input the real-time feed flow rate S and the real-time load monitoring value A into the fault type determination model to determine the fault type.

[0042] As a preferred solution, the load monitoring value of the transmission device is one or more of the following: the current value of the centrifuge motor, the current value of the frequency converter controlling the centrifuge motor, and the torque value of the centrifuge transmission shaft system.

[0043] In addition, in another aspect, the present invention discloses a fault detection system for a centrifuge, comprising:

[0044] A feeding device is installed at the feeding end of the centrifuge and is used to collect the feeding flow in real time;

[0045] A detection device, the detection device is used to perform load detection on the transmission device of the centrifuge;

[0046] A control device, the control device is used to execute the fault detection method according to any one of claims 1-8.

[0047] The present invention discloses a centrifuge fault detection method and system, which has the following features:

[0048] Beneficial effects:

[0049] First, the present invention detects the centrifuge in the startup stage and the working stage, takes the load monitoring value of the transmission device and the feed flow rate as the entry point, and jointly makes a judgment. When the transmission device of the existing centrifuge fails, it can be quickly discovered and withdrawn from the production operation stage in time.

[0050] Secondly, the present invention establishes a fault type determination model to determine the fault type of the transmission device, providing a reference for the staff so that the problem can be discovered and solved quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 A schematic diagram of a fault detection system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] The expression of “comprising” an element is an “open” expression, which merely means that a corresponding component or step exists, and should not be interpreted as excluding additional components or steps.

[0056] In order to achieve the purpose of the present invention, in some embodiments of the fault detection method and system for a centrifuge, the fault detection method includes:

[0057] Step S1: when the feed flow rate of the feed device is zero, record the load monitoring value A0 of the transmission device of the centrifuge under normal operating conditions, that is, the load monitoring value when no load;

[0058] Step S3: In the actual production stage, the feed flow rate S of the feed device and the load monitoring value A of the transmission device are detected in real time;

[0059] If A≤A0 and S>0, the transmission device of the centrifuge fails, and the feeding device and the transmission device stop operating.

[0060] The load monitoring value of the transmission device is one or more of the following: the current value of the centrifuge motor, the current value of the frequency converter controlling the centrifuge motor, and the torque value of the centrifuge transmission shaft system.

[0061] Example:

[0062] Taking LW800 horizontal screw centrifuge as an example, the no-load current of LW800 centrifuge is 82A and the no-load torque is 8%.

[0063] In the actual production stage, the load current of the LW800 horizontal screw centrifuge is about 160A, and the load torque is about 55%. If the working current of the centrifuge suddenly drops to about 80A or the torque suddenly drops to 8% or lower (lower than the no-load current and no-load torque), and the feed flow rate of the centrifuge is detected to be greater than 0, the transmission device of the centrifuge fails, the transmission device fails, the feed device of the centrifuge stops working, the centrifuge stops feeding, the transmission device stops working, and an alarm is issued.

[0064] The present invention can effectively prevent the inside of the centrifuge from being blocked by materials, thereby avoiding damage to the centrifuge.

[0065] In order to further optimize the implementation effect of the present invention, in some other embodiments, the remaining characteristic technologies are the same, except that step S1 is further:

[0066] Record the load monitoring value As of the transmission device when the centrifuge is started;

[0067] When the feed flow rate of the feed device is zero, record the load monitoring value A0 of the transmission device of the centrifuge under normal operating conditions.

[0068] Step S3 is further as follows:

[0069] During the startup phase, the load monitoring value A of the transmission device is detected in real time;

[0070] If A≤a*As, or A fluctuates greatly, the centrifuge fails, and the feeding device and transmission device stop working;

[0071] Where: a is the preset parameter;

[0072] In the actual production stage, the feed flow S of the feed device and the load monitoring value A of the transmission device are detected in real time;

[0073] If A≤A0 and S>0, the transmission device of the centrifuge fails, and the feeding device and the transmission device stop operating.

[0074] Example:

[0075] Taking the LW800 horizontal screw centrifuge as an example, when the centrifuge is started, the starting current of the LW800 horizontal screw centrifuge is about 200A, and the starting torque is about 70%. When it is detected that the starting current or starting torque of the centrifuge is far lower than the preset value or fluctuates greatly, the feeding device of the centrifuge stops working, the centrifuge stops feeding, the transmission device stops working, and an alarm is sounded.

[0076] The present invention can detect centrifuge failure during the startup phase, and prevent the centrifuge from being put into production operation in a failure state.

[0077] In order to further optimize the implementation effect of the present invention, in some other implementations, the remaining characteristic technologies are the same, except that between step S1 and step S3, the following is further included:

[0078] Step S2: The centrifuge is simulated under each fault state of the transmission device, and the relationship between the feed flow rate S and the load monitoring value A is recorded. Based on the relationship between the feed flow rate S and the load monitoring value A under different faults, a fault type determination model is trained. The fault type determination model is used to determine the corresponding fault type according to the real-time feed flow rate S and the load monitoring value A.

[0079] The present invention finds that there is a relationship between the feed flow rate and the load monitoring value for different fault types. Based on this relationship, a fault type determination model is constructed.

[0080] Further, step S2 comprises:

[0081] Step S2.1: Classify the fault types of the transmission device into three types, such as belt breakage, drive shaft breakage, and coupling disengagement;

[0082] Step S2.2: Divide the feed flow rate into 10 types according to the minimum threshold value Smin to the maximum threshold value Smax;

[0083] Step S2.3: When the centrifuge is in normal operation and the feed flow rate is stable at any type, any type of fault of the transmission device is simulated to record the load monitoring value;

[0084] Step S2.4: Repeat step S2.3 until all 10 feed flow rates are simulated;

[0085] Step S2.5: Repeat steps S2.3 to S2.4 until all three fault types are simulated;

[0086] Step S2.6: fuzzify the precise values ​​of the 10 feed flow rates to obtain a fuzzy set;

[0087] Step S2.7: Establish a simulation database, in which the fuzzy set under each fault type and its corresponding load detection value are stored;

[0088] Step S2.8: Divide the data in the simulation database into a training set and a test set;

[0089] Step S2.9: Establish a fault type determination model;

[0090] Step S2.10: Use the training set to train the fault type determination model, and then use the test set to test and verify it.

[0091] Furthermore, when step S3 detects that the transmission device of the centrifuge fails, the feeding device and the transmission device stop operating, and step S4 is further executed. Step S4 is used to determine the fault type of the transmission device using a fault type determination model.

[0092] Further, step S4 includes:

[0093] Step S4.1: Record the real-time feed flow rate S and the real-time load monitoring value A when the transmission device fails;

[0094] Step S4.2: input the real-time feed flow rate S and the real-time load monitoring value A into the fault type determination model to determine the fault type.

[0095] The invention discloses a fault type determination model, which can quickly find out the fault type and facilitate timely maintenance by staff.

[0096] Further, in some other embodiments, step S2 may include:

[0097] Step S2.1: Classify the fault types of the transmission device into N types;

[0098] Step S2.2: Divide the feed flow rate into M types according to the minimum threshold value Smin to the maximum threshold value Smax;

[0099] Step S2.3: When the centrifuge is in normal operation and the feed flow rate is stable at any type, any type of fault of the transmission device is simulated to record the load monitoring value;

[0100] Step S2.4: Repeat step S2.3 until all M feed flow rates are simulated;

[0101] Step S2.5: Repeat steps S2.3 to S2.4 until all N types of faults are simulated;

[0102] Step S2.6: Based on the data of the feed flow rate S and the load monitoring value A of each fault type, fitting is performed to establish the SA curve of each fault type to form a fault type determination model.

[0103] Then, further step S4 comprises:

[0104] Step S4.1: Record the real-time feed flow rate S and the real-time load monitoring value A when the transmission device fails;

[0105] Step S4.2: The real-time feed flow rate S and the real-time load monitoring value A form a real-time monitoring point, which is input into the fault type determination model, and the nearest points (e.g., 3) to the real-time monitoring point are found from the SA curve of each fault type, and the sum of the distance values ​​between the real-time monitoring point and the nearest points is calculated;

[0106] The fault type corresponding to the sum of the minimum distance values ​​is taken as the judgment result and output.

[0107] In addition, an embodiment of the present invention discloses a fault detection system for a centrifuge, such as Figure 1 As shown, including:

[0108] A feeding device is installed at the feeding end of the centrifuge and is used to collect the feeding flow in real time;

[0109] A detection device, the detection device is used to perform load detection on the transmission device of the centrifuge;

[0110] A control device, the control device is used to execute the fault detection method disclosed in any of the above embodiments.

[0111] It is worth noting that the feeding device may include, but is not limited to, a flow monitoring sensor installed on a feeding pump or a feeding valve.

[0112] In some other embodiments, the fault detection system may further include: a PLC.

[0113] The present invention discloses a centrifuge fault detection method and system, which has the following features:

[0114] Beneficial effects:

[0115] First, the present invention detects the centrifuge in the startup stage and the working stage, takes the load monitoring value of the transmission device and the feed flow rate as the entry point, and jointly makes a judgment. When the transmission device of the existing centrifuge fails, it can be quickly discovered and withdrawn from the production operation stage in time.

[0116] Secondly, the present invention establishes a fault type determination model to determine the fault type of the transmission device, providing a reference for the staff so that the problem can be discovered and solved quickly.

[0117] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A fault detection method for a centrifuge, characterized in that: include: Step S1: when the feed flow rate of the feed device is zero, record the load monitoring value A0 of the transmission device of the centrifuge under normal operating conditions; Step S3: In the actual production stage, the feed flow rate S of the feed device and the load monitoring value A of the transmission device are detected in real time; If A≤A0 and S>0, the transmission device of the centrifuge fails, and the feeding device and the transmission device stop operating.

2. The fault detection method according to claim 1, characterized in that: The step S1 is further as follows: Record the load monitoring value As of the transmission device when the centrifuge is started; When the feed flow rate of the feed device is zero, record the load monitoring value A0 of the transmission device of the centrifuge under normal operating conditions.

3. The fault detection method according to claim 2, characterized in that: The step S3 is further as follows: During the startup phase, the load monitoring value A of the transmission device is detected in real time; If A≤a*As, or A fluctuates greatly, the centrifuge fails, and the feeding device and transmission device stop working; Where: a is the preset parameter; In the actual production stage, the feed flow S of the feed device and the load monitoring value A of the transmission device are detected in real time; If A≤A0 and S>0, the transmission device of the centrifuge fails, and the feeding device and the transmission device stop operating.

4. The fault detection method according to any one of claims 1 to 3, characterized in that: Between step S1 and step S3, the method further includes: Step S2: The centrifuge is simulated under each fault state of the transmission device, and the relationship between the feed flow rate S and the load monitoring value A is recorded. Based on the relationship between the feed flow rate S and the load monitoring value A under different faults, a fault type determination model is trained. The fault type determination model is used to determine the corresponding fault type according to the real-time feed flow rate S and the load monitoring value A.

5. The fault detection method according to claim 4, characterized in that: The step S2 comprises: Step S2.1: Classify the fault types of the transmission device into N types; Step S2.2: Divide the feed flow rate into M types according to the minimum threshold value Smin to the maximum threshold value Smax; Step S2.3: When the centrifuge is in normal operation and the feed flow rate is stable at any type, any type of fault of the transmission device is simulated to record the load monitoring value; Step S2.4: Repeat step S2.3 until all M feed flow rates are simulated; Step S2.5: Repeat steps S2.3 to S2.4 until all N types of faults are simulated; Step S2.6: fuzzify the precise values ​​of the M types of feed flow rates to obtain a fuzzy set; Step S2.7: Establish a simulation database, in which the fuzzy set under each fault type and its corresponding load detection value are stored; Step S2.8: Divide the data in the simulation database into a training set and a test set; Step S2.9: Establish a fault type determination model; Step S2.10: Use the training set to train the fault type determination model, and then use the test set to test and verify it.

6. The fault detection method according to claim 5, characterized in that: When it is detected in step S3 that the transmission device of the centrifuge fails, the feeding device and the transmission device stop operating, and step S4 is further executed. The step S4 is used to determine the fault type of the transmission device using a fault type determination model.

7. The fault detection method according to claim 6, characterized in that: The step S4 comprises: Step S4.1: Record the real-time feed flow rate S and the real-time load monitoring value A when the transmission device fails; Step S4.2: input the real-time feed flow rate S and the real-time load monitoring value A into the fault type determination model to determine the fault type.

8. The fault detection method according to claim 1, characterized in that: The load monitoring value of the transmission device is one or more of the following: the current value of the centrifuge motor, the current value of the frequency converter controlling the centrifuge motor, and the torque value of the centrifuge transmission shaft system.

9. A fault detection system for a centrifuge, characterized in that: include: A feeding device, which is installed at the feeding end of the centrifuge and is used to collect the feeding flow in real time; A detection device, the detection device is used to perform load detection on the transmission device of the centrifuge; A control device, wherein the control device is used to execute the fault detection method according to any one of claims 1 to 8.

Images