Remote fault diagnosis system for air compressor

Abstract

The invention discloses a remote fault diagnosis system for an air compressor, relates to the technical field of fault diagnosis, and can realize early warning and accurate diagnosis of a rotor clearance problem by collecting key parameters in the operation process of the air compressor and combining multiple dimensions such as rotor wear evaluation and clearance abnormity judgment. The maintenance efficiency and the operation reliability of the equipment are improved; specifically, comprehensive monitoring and efficient diagnosis of the running state of the rotor in the spiral air compressor are realized through modular design and in combination with data acquisition, rotor evaluation, fault diagnosis and remote management functions; the system depends on an accurate real-time data acquisition and multi-parameter comprehensive analysis technology, various common faults including rotor abrasion, gap abnormity, insufficient lubrication and the like can be quickly found, and the diagnosis precision and efficiency are remarkably improved; besides, the system supports remote management and classified maintenance operation, and fault information is generated and transmitted in time, so that the problem response time is greatly shortened, the shutdown loss is reduced, and the maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of fault diagnosis, and in particular to a remote fault diagnosis system for an air compressor. Background Art

[0002] Screw air compressor is an important equipment widely used in industrial production. Its core component is a pair of intermeshing screw rotors. During the operation of the air compressor, the meshing clearance between the rotors plays a key role in the performance and reliability of the equipment. However, due to factors such as mechanical wear and thermal fatigue during long-term operation, the rotor clearance will gradually increase, which will not only lead to a decrease in compression efficiency, but also increase gas leakage, ultimately affecting the overall performance of the equipment.

[0003] At present, the detection of abnormal rotor clearance of screw air compressors mainly relies on regular maintenance and manual inspection. This method has the following problems: First, since the rotor is inside the equipment, manual detection is difficult and it is impossible to grasp the changes in the rotor clearance in real time; second, traditional detection methods often can only find problems after the failure occurs, making it difficult to achieve preventive maintenance; third, the factors that affect the abnormal rotor clearance are complex, including insufficient lubrication, mechanical wear, thermal fatigue and other aspects. It is difficult to accurately determine the cause of the failure by relying solely on manual experience.

[0004] In order to ensure the reliable operation of screw air compressors, a remote diagnosis system is urgently needed that can monitor the rotor clearance status in real time and accurately diagnose the cause of the fault. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an air compressor remote fault diagnosis system, which solves the problems in the background technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: an air compressor remote fault diagnosis system, comprising:

[0007] A data acquisition module is used to collect real-time key parameters of the air compressor and send the collected real-time key parameters to the subsequent rotor wear assessment module and rotor clearance abnormality judgment module;

[0008] A rotor wear assessment module, which is used to receive real-time key parameters, determine a theoretical value of gas flow and a gas flow leakage according to the real-time key parameters, and determine a rotor wear assessment coefficient in combination with the real-time key parameters;

[0009] A rotor clearance abnormality judgment module is used to receive real-time key parameters and obtain the gas flow leakage in the rotor wear assessment module, determine the rotor clearance assessment value in combination with the rotor wear assessment coefficient, and judge whether the rotor clearance is abnormal according to the size of the rotor clearance assessment value. When it is judged that the rotor clearance is abnormal, diagnostic information is generated and sent to the subsequent diagnostic module;

[0010] The fault diagnosis module is used to receive the diagnostic information. When the diagnostic information is received, the operating parameters of the air compressor are obtained, analyzed, and the main reasons for generating the diagnostic information are determined.

[0011] As a further solution of the present invention: in the data acquisition module, the real-time key parameters include the real-time intake pressure, the real-time exhaust pressure, the real-time intake temperature, the real-time exhaust temperature and the real-time actual gas flow rate during the operation of the compressor;

[0012] In the fault diagnosis module, the air compressor operating parameters include: lubricating oil pressure, lubricating oil temperature, lubricating oil flow, the total running time of the air compressor from the start of operation to the current moment, the real-time speed of the rotor at each moment, the real-time input and output air pressure difference at each moment, and the real-time operating temperature of the rotor at each moment.

[0013] As a further solution of the present invention: the diagnostic module includes a lubrication monitoring diagnostic unit, a normal operation diagnostic unit and an other factor diagnostic unit;

[0014] A lubrication monitoring and diagnostic unit; used to determine a lubrication evaluation coefficient according to working parameters, and to determine whether to generate lubrication fault information according to the lubrication evaluation coefficient;

[0015] A normal operation diagnosis unit, used to determine a working rotor clearance increment coefficient according to working parameters, and determine whether to generate a working operation clearance increase fault information according to the working rotor clearance increment coefficient;

[0016] The other factor diagnosis unit is used to generate other fault information when the lubrication monitoring diagnosis unit and the normal operation diagnosis unit do not generate corresponding fault information.

[0017] As a further solution of the present invention: in the rotor wear assessment module, the specific method of determining the theoretical value of the gas flow and the gas flow leakage according to the real-time key parameters and determining the rotor wear assessment coefficient in combination with the real-time key parameters is:

[0018] AS1: Obtain the real-time intake pressure, real-time exhaust pressure, real-time intake temperature, real-time exhaust temperature and real-time actual gas flow rate among the real-time key parameters, and mark them as: P in , P out 、T in 、T out, Q actual ; The theoretical value of gas flow Q is determined by the following formula theoretical :

[0019]

[0020] In the formula, k is the impact factor;

[0021] AS2: Get the theoretical value Q of gas flow theoretical and the real-time actual gas flow Q actual , calculate the difference between the two and determine the gas flow leakage Q leak ; and the wear clearance area index A is determined by the following formula w ;

[0022]

[0023] In the formula, C d It is expressed as the flow coefficient, and ρ is expressed as the gas density;

[0024] AS3: According to the law of energy conservation, the theoretical exhaust temperature T is determined by the following formula out,ideal :

[0025]

[0026] Where η is the compression efficiency;

[0027] AS4: According to the wear clearance area index A w and theoretical exhaust temperature T out,ideal , the rotor wear assessment factor is determined by the following formula:

[0028]

[0029] Where W is the rotor wear assessment coefficient.

[0030] As a further solution of the present invention: in the rotor clearance abnormality judgment module, the specific contents of receiving the real-time key parameters and obtaining the gas flow leakage in the rotor wear assessment module, determining the rotor clearance assessment value in combination with the rotor wear assessment coefficient, and judging whether the rotor clearance is abnormal according to the size of the rotor clearance assessment value include:

[0031] Obtain the real-time intake pressure P among the real-time key parameters in , Real-time exhaust pressure P out , Real-time intake air temperature T in and gas flow leakage Q leak , combined with the rotor wear evaluation coefficient W, the rotor clearance evaluation value is determined by the following formula:

[0032]

[0033] Where, δ is the rotor clearance evaluation value;

[0034] Compare the rotor clearance evaluation value δ with the threshold value G1:

[0035] If δ>G1, it is judged that the rotor clearance is abnormal and the diagnostic information is generated;

[0036] If δ≤G1, it is judged that the rotor clearance is abnormal and no treatment is performed;

[0037] Among them, the threshold G1 is a preset value.

[0038] As a further solution of the present invention: in the lubrication monitoring and diagnosis unit, the specific method of determining the lubrication evaluation coefficient according to the working parameters and determining whether to generate lubrication fault information according to the lubrication evaluation coefficient is:

[0039] BS1: Obtain the lubricating oil pressure, lubricating oil temperature and lubricating oil flow rate in the working parameters, and record them as P o , T o and Q o ;

[0040] BS2: Determine the lubrication pressure contribution factor L by the following formula: P :

[0041]

[0042] Where P ideal Expressed as the ideal lubrication pressure, σ P Expressed as the normal fluctuation range above and below the ideal lubrication pressure;

[0043] The lubrication temperature contribution factor is determined by the following formula:

[0044]

[0045] Where, T ideal Expressed as the ideal lubrication temperature, σ T Expressed as the normal fluctuation range above and below the ideal lubrication temperature;

[0046] The lubrication flow contribution factor is determined by the following formula:

[0047]

[0048] In the formula, Q ideal Expressed as ideal lubricating oil flow rate;

[0049] BS3: Get the lubrication pressure contribution factor L P , Lubrication temperature contribution factor LT and lubrication flow contribution factor L Q , determine the lubrication evaluation factor L by the following formula:

[0050] L=w1·L P +w2·L T +w3·L Q

[0051] BS4: Lubrication evaluation coefficient L and threshold L thre For comparison:

[0052] If L <L thre , it is determined that there is a problem with the lubrication coefficient and lubrication fault information is generated; no processing is performed in other cases; the threshold L thre is the default value.

[0053] As a further solution of the present invention: in the normal operation diagnosis unit, the specific method of determining the working rotor clearance increment coefficient according to the working parameters and determining whether to generate the working operation clearance increase fault information according to the working rotor clearance increment coefficient is as follows;

[0054] CS1: Obtain the total operating time of the air compressor from the start of operation to the current moment, the real-time speed of the rotor at each moment, the difference between the input and output air pressures at each moment, and the real-time working temperature of the rotor at each moment, and record them as t, N(τ), ΔP(τ) and T(τ) respectively;

[0055] CS2: The gap increment caused by cumulative wear is determined by the following formula:

[0056]

[0057] In the formula, κ w is the wear coefficient of the rotor material, N(τ) is the speed at time τ; ΔP(τ): the difference between the input and output air pressures at time τ;

[0058] CS3: The gap increase caused by thermal fatigue is determined by the following formula:

[0059]

[0060] In the formula, κ t is the thermal expansion coefficient of the rotor material; T(τ) is the temperature at time τ; n is the exponent of the effect of temperature on thermal expansion;

[0061] CS4: Combine the gap increment caused by cumulative wear and the gap increment caused by thermal fatigue to determine the working rotor gap increment coefficient ΔG(t): ΔG(t) = Δ wear (t)+Δ thermal (t);

[0062] Compare the rotor clearance increment coefficient ΔG(t) with the rotor clearance evaluation value δ:

[0063] If ΔG(t)≥δ, a fault message of increased working gap is generated;

[0064] If ΔG(t)<δ, no processing is done.

[0065] As a further solution of the present invention: it also includes: a remote management and maintenance module, which is used to receive corresponding fault information generated by the diagnosis module, and arrange relevant maintenance personnel to perform on-site maintenance according to the corresponding fault information generated.

[0066] The present invention provides a remote fault diagnosis system for air compressors. Compared with the prior art, it has the following beneficial effects:

[0067] The present invention can achieve early warning and accurate diagnosis of rotor clearance problems by collecting key parameters during the operation of the air compressor and combining multiple dimensions such as rotor wear assessment and clearance abnormality judgment, thereby improving the maintenance efficiency and operational reliability of the equipment.

[0068] The present invention realizes comprehensive monitoring and efficient diagnosis of the rotor operating status in the screw air compressor through modular design, combined with data acquisition, rotor evaluation, fault diagnosis and remote management functions. Relying on accurate real-time data acquisition and multi-parameter comprehensive analysis technology, the system can quickly detect a variety of common faults including rotor wear, gap abnormalities, insufficient lubrication, etc., significantly improving the diagnostic accuracy and efficiency. In addition, the system supports remote management and classified maintenance operations, and by timely generating and transmitting fault information, it greatly shortens the problem response time, reduces downtime losses and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The present invention will be further described below in conjunction with the accompanying drawings.

[0070] Figure 1 The present invention is a structural framework diagram of an air compressor remote fault diagnosis system.

[0071] Figure 2 The present invention is a schematic diagram of the internal fault diagnosis of an air compressor remote fault diagnosis system. DETAILED DESCRIPTION

[0072] 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.

[0073] Embodiment 1

[0074] See also Figure 1 and Figure 2 ,The present invention provides an air compressor remote fault diagnosis system, comprising;

[0075] A data acquisition module is used to collect real-time key parameters of the air compressor and send the collected real-time key parameters to the subsequent rotor wear assessment module and rotor clearance abnormality judgment module;

[0076] The real-time key parameters include the real-time intake pressure, real-time exhaust pressure, real-time intake temperature, real-time exhaust temperature and real-time actual gas flow rate during the operation of the compressor;

[0077] It should be noted that the input air pressure sensor is installed in front of the air compressor inlet to monitor the pressure of the air intake pipeline; the output air pressure sensor is installed behind the air compressor exhaust port to monitor the pressure of the exhaust pipeline. The pressure sensor senses the change of gas pressure in the pipeline through the principle of resistance strain gauge or piezoelectric sensor, and converts it into an electrical signal. The output signal of the pressure sensor is read in real time through the data acquisition system and converted into a standard pressure value; the input air temperature sensor is installed at the air compressor inlet to detect the temperature of the air entering the air compressor; the output air temperature sensor is installed at the exhaust port of the air compressor to monitor the temperature of the compressed air; commonly used temperature sensors include thermocouples (such as K type) and RTD (platinum resistance temperature detector); these sensors convert temperature changes into voltage or resistance changes and transmit them to the data acquisition system; the flow sensor is usually installed in the exhaust duct, close to the exhaust port of the air compressor, so as to measure the flow of the output gas in real time;

[0078] A rotor wear assessment module, which is used to receive real-time key parameters, determine a theoretical value of gas flow and a gas flow leakage according to the real-time key parameters, and determine a rotor wear assessment coefficient in combination with the real-time key parameters;

[0079] The specific method of determining the theoretical value of the gas flow and the gas flow leakage according to the real-time key parameters and determining the rotor wear assessment coefficient in combination with the real-time key parameters is:

[0080] AS1: Obtain the real-time intake pressure, real-time exhaust pressure, real-time intake temperature, real-time exhaust temperature and real-time actual gas flow rate among the real-time key parameters, and mark them as: P in , P out , T in , T out , Q actual ; The theoretical value of gas flow Q is determined by the following formula theoretical :

[0081]

[0082] In the formula, k is the influencing factor, which is a constant and is determined according to the model of the screw air compressor;

[0083] AS2: Get the theoretical value Q of gas flow theoretical and the real-time actual gas flow Q actual , calculate the difference between the two and determine the gas flow leakage Q leak ; and the wear clearance area index A is determined by the following formula w ;

[0084]

[0085] In the formula, C d It is expressed as the flow coefficient (related to the properties of the gas), which is specifically defined by people in this professional field, and ρ is expressed as the gas density;

[0086] AS3: According to the law of energy conservation, the theoretical exhaust temperature T is determined by the following formula out,ideal :

[0087]

[0088] Where η is the compression efficiency;

[0089] AS4: According to the wear clearance area index A w and theoretical exhaust temperature T out,ideal , the rotor wear assessment factor is determined by the following formula:

[0090]

[0091] Where W represents the rotor wear assessment coefficient;

[0092] It should be noted that the wear of the screw rotor will lead to an increase in the meshing clearance, resulting in an increase in gas leakage, which will lead to a decrease in the actual gas flow rate and a decrease in the compression efficiency, which is specifically manifested in the deviation of the exhaust pressure and temperature;

[0093] A rotor clearance abnormality judgment module is used to receive real-time key parameters and obtain the gas flow leakage in the rotor wear assessment module, determine the rotor clearance assessment value in combination with the rotor wear assessment coefficient, and judge whether the rotor clearance is abnormal according to the size of the rotor clearance assessment value. When it is judged that the rotor clearance is abnormal, diagnostic information is generated and sent to the subsequent diagnostic module;

[0094] The specific contents of receiving the real-time key parameters and obtaining the gas flow leakage in the rotor wear assessment module, determining the rotor clearance assessment value in combination with the rotor wear assessment coefficient, and judging whether the rotor clearance is abnormal according to the size of the rotor clearance assessment value include:

[0095] Obtain the real-time intake pressure P among the real-time key parameters in , Real-time exhaust pressure P out , Real-time intake air temperature T in and gas flow leakage Q leak , combined with the rotor wear evaluation coefficient W, the rotor clearance evaluation value is determined by the following formula:

[0096]

[0097] Where, δ is the rotor clearance evaluation value;

[0098] Compare the rotor clearance evaluation value δ with the threshold value G1:

[0099] If δ>G1, it is judged that the rotor clearance is abnormal and the diagnostic information is generated;

[0100] If δ≤G1, it is judged that the rotor clearance is abnormal and no treatment is performed;

[0101] The threshold value G1 is a preset value, which is determined by professional staff. In this embodiment, the threshold value G1 is a factory standard value, which is usually provided by the manufacturer. G1=f(d totor ,l rotor ), d totor is the rotor diameter, l rotor is the rotor length, f is the manufacturing process function;

[0102] This module calculates the rotor clearance assessment value by comprehensively analyzing the real-time collected parameters, rotor wear assessment coefficient and gas flow leakage, and compares it with the preset threshold to determine whether there is an abnormality. Based on the assessment value, diagnostic information is generated, enabling the system to quickly locate the abnormal rotor clearance problem. This module effectively improves the accuracy and response speed of fault warning.

[0103] A fault diagnosis module is used to receive diagnostic information. When receiving the diagnostic information, it obtains the working parameters of the air compressor, analyzes the parameters, and determines the main reasons for generating the diagnostic information. The diagnostic module includes a lubrication monitoring diagnostic unit, a normal operation diagnostic unit, and other factor diagnostic units;

[0104] The working parameters include: lubricating oil pressure, lubricating oil temperature, lubricating oil flow, total running time of the air compressor from the start of operation to the current moment, real-time rotor speed at each moment, real-time input and output air pressure difference at each moment, and real-time rotor working temperature at each moment;

[0105] It should be noted that the real-time speed of the rotor at each moment, the real-time input and output pressure difference at each moment, and the real-time working temperature of the rotor at each moment are collected once at a preset interval, and each parameter in the working parameters is obtained by a corresponding sensor;

[0106] A lubrication monitoring and diagnostic unit; used to determine a lubrication evaluation coefficient according to working parameters, and to determine whether to generate lubrication fault information according to the lubrication evaluation coefficient;

[0107] The specific method of determining the lubrication evaluation coefficient according to the working parameters and determining whether to generate lubrication fault information according to the lubrication evaluation coefficient is as follows:

[0108] BS1: Obtain the lubricating oil pressure, lubricating oil temperature and lubricating oil flow rate in the working parameters, and record them as P o 、T o and Q o ;

[0109] BS2: Determine the lubrication pressure contribution factor L by the following formula: P :

[0110]

[0111] Where P ideal Expressed as the ideal lubrication pressure, σ P Expressed as the normal fluctuation range above and below the ideal lubrication pressure;

[0112] The lubrication temperature contribution factor is determined by the following formula:

[0113]

[0114] Where, T ideal Expressed as the ideal lubrication temperature, σ T Expressed as the normal fluctuation range above and below the ideal lubrication temperature;

[0115] The lubrication flow contribution factor is determined by the following formula:

[0116]

[0117] In the formula, Q ideal Expressed as ideal lubricating oil flow rate;

[0118] BS3: Get the lubrication pressure contribution factor L P , Lubrication temperature contribution factor L T and lubrication flow contribution factor L Q , determine the lubrication evaluation factor L by the following formula:

[0119] L=w1·L P +w2·L T +w3·L Q

[0120] BS4: Lubrication evaluation coefficient L and threshold L thre For comparison:

[0121] If L <L thre , it is determined that there is a problem with the lubrication coefficient and lubrication fault information is generated; no processing is performed in other cases; the threshold L thre It is a preset value, which will be determined by professional staff;

[0122] A normal operation diagnosis unit, used to determine a working rotor clearance increment coefficient according to working parameters, and determine whether to generate a working operation clearance increase fault information according to the working rotor clearance increment coefficient;

[0123] The specific method of determining the working rotor clearance increment coefficient according to the working parameters and determining whether to generate the working operation clearance increase fault information according to the working rotor clearance increment coefficient is as follows;

[0124] CS1: Obtain the total operating time of the air compressor from the start of operation to the current moment, the real-time speed of the rotor at each moment, the difference between the input and output air pressures at each moment, and the real-time working temperature of the rotor at each moment, and record them as t, N(τ), ΔP(τ) and T(τ) respectively;

[0125] CS2: The gap increment caused by cumulative wear is determined by the following formula:

[0126]

[0127] In the formula, κ w is the wear coefficient of the rotor material, N(τ) is the speed at time τ; ΔP(τ): the difference between the input and output air pressures at time τ;

[0128] CS3: The gap increase caused by thermal fatigue is determined by the following formula:

[0129]

[0130] In the formula, κ t is the thermal expansion coefficient of the rotor material; T(τ) is the temperature at time τ; n is the exponent of the effect of temperature on thermal expansion (usually 2 or 3, determined according to the material properties);

[0131] CS4: Combine the gap increment caused by cumulative wear and the gap increment caused by thermal fatigue to determine the working rotor gap increment coefficient ΔG(t): ΔG(t) = Δ wear (t)+Δthermal (t);

[0132] Compare the rotor clearance increment coefficient ΔG(t) with the rotor clearance evaluation value δ:

[0133] If ΔG(t)≥δ, it indicates that the gap increases due to long-term operation, and the fault information of the gap increase during operation is generated;

[0134] If ΔG(t)<δ, no treatment is performed;

[0135] Other factor diagnosis unit, used for generating other fault information when the lubrication monitoring diagnosis unit and the normal operation diagnosis unit do not generate corresponding fault information;

[0136] Abnormal rotor clearance is a common fault of screw air compressors. The main reasons are usually attributed to insufficient lubrication system and natural wear and clearance increase caused by long-term operation. Insufficient lubrication will increase the friction on the rotor surface and cause abnormal wear. Long-term operation will cause the matching accuracy between the rotors to decrease due to continuous mechanical stress and fatigue, so that the clearance gradually increases. Therefore, when diagnosing abnormal rotor clearance, it is necessary to first check the operating status of the lubrication system, including whether the amount of lubricating oil is sufficient, whether the oil is aged, and whether the lubrication pipeline is unobstructed. At the same time, check the operating time and maintenance records of the equipment to determine whether it is natural wear. When the above two factors are excluded, the clearance abnormality can be attributed to other possible factors.

[0137] The fault diagnosis module combines the lubrication monitoring diagnosis unit, normal operation diagnosis unit and other factor diagnosis units to comprehensively analyze the faults of the air compressor based on the lubrication status, operating parameters and other potential causes. The lubrication monitoring unit evaluates the lubrication status through the contribution factors of pressure, temperature and flow, and promptly detects the problem of insufficient lubrication. The normal operation diagnosis unit determines the natural wear caused by long-term operation through the working clearance increment coefficient. The other factor diagnosis unit supplements the detection capability of unknown problems in addition to the conventional diagnosis, so as to further clarify the root cause of the fault and take targeted measures to solve the problem.

[0138] A remote management and maintenance module is used to receive the corresponding fault information generated by the diagnosis module and arrange relevant maintenance personnel to perform on-site maintenance according to the corresponding fault information generated;

[0139] Specifically, there are four situations in which the receiving diagnosis module generates corresponding fault information. The first is to receive only lubrication fault information, the second is to receive only working operation gap increase fault information, the third is to receive lubrication fault information and working operation gap increase fault information, and the fourth is to receive other fault information; relevant maintenance personnel make corresponding maintenance operations according to these four types of fault information to improve maintenance efficiency.

[0140] Embodiment 2

[0141] In the specific implementation process, this embodiment is based on the first embodiment and is different from the first embodiment in that the compression efficiency η of step AS3 in the specific method of determining the theoretical value of the gas flow rate and the gas flow leakage according to the real-time key parameters and determining the rotor wear evaluation coefficient in combination with the real-time key parameters is determined;

[0142] In step AS3, η is the compression efficiency and is determined as follows:

[0143] AS31: Ideally, the compressor should perform isentropic compression (i.e. a process without heat loss). Under isentropic conditions, the compression work of the gas is calculated by the following formula:

[0144]

[0145] Where W ideal is the ideal compression work, R is the gas constant, T1 is the intake temperature (absolute temperature), P1 is the intake pressure, P2 is the exhaust pressure, and b is the specific heat ratio of the gas (generally for air, b≈1.4);

[0146] AS32: In the actual compression process, due to friction, heat loss, fluid resistance and other reasons, the actual power consumption of the air compressor is usually higher than the ideal power consumption; the actual compression work W actual Calculated by the following formula:

[0147]

[0148] Where: W actual is the actual compression work, V1 is the intake volume flow rate, η actual is the actual compression efficiency, and W input It is the actual energy input when the air compressor is running (motor input power);

[0149] AS33: The compression efficiency η is calculated by comparing the actual power consumption with the ideal power consumption, and the formula is

[0150] Embodiment 3

[0151] The specific implementation process of this embodiment includes the entire implementation process of the above two groups of embodiments.

[0152] Some of the data in the above formulas are dimensionless and numerically calculated. Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0153] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A remote fault diagnosis system for an air compressor, characterized in that: include: A data acquisition module is used to collect real-time key parameters of the air compressor and send the collected real-time key parameters to the subsequent rotor wear assessment module and rotor clearance abnormality judgment module; A rotor wear assessment module, which is used to receive real-time key parameters, determine a theoretical value of gas flow and a gas flow leakage according to the real-time key parameters, and determine a rotor wear assessment coefficient in combination with the real-time key parameters; A rotor clearance abnormality judgment module is used to receive real-time key parameters and obtain the gas flow leakage in the rotor wear assessment module, determine the rotor clearance assessment value in combination with the rotor wear assessment coefficient, and judge whether the rotor clearance is abnormal according to the size of the rotor clearance assessment value. When it is judged that the rotor clearance is abnormal, diagnostic information is generated and sent to the subsequent diagnostic module; The fault diagnosis module is used to receive the diagnostic information. When the diagnostic information is received, the operating parameters of the air compressor are obtained, analyzed, and the main reasons for generating the diagnostic information are determined.

2. The air compressor remote fault diagnosis system according to claim 1, characterized in that: In the data acquisition module, the real-time key parameters include the real-time intake pressure, real-time exhaust pressure, real-time intake temperature, real-time exhaust temperature and real-time actual gas flow rate during the operation of the compressor; In the fault diagnosis module, the air compressor operating parameters include: lubricating oil pressure, lubricating oil temperature, lubricating oil flow, the total running time of the air compressor from the start of operation to the current moment, the real-time speed of the rotor at each moment, the real-time input and output air pressure difference at each moment, and the real-time operating temperature of the rotor at each moment.

3. The air compressor remote fault diagnosis system according to claim 2, characterized in that: The diagnostic module includes a lubrication monitoring diagnostic unit, a normal operation diagnostic unit, and other factor diagnostic units; A lubrication monitoring and diagnostic unit; used to determine a lubrication evaluation coefficient according to working parameters, and to determine whether to generate lubrication fault information according to the lubrication evaluation coefficient; A normal operation diagnosis unit, used to determine a working rotor clearance increment coefficient according to working parameters, and determine whether to generate a working operation clearance increase fault information according to the working rotor clearance increment coefficient; The other factor diagnosis unit is used to generate other fault information when the lubrication monitoring diagnosis unit and the normal operation diagnosis unit do not generate corresponding fault information.

4. The air compressor remote fault diagnosis system according to claim 3, characterized in that: In the rotor wear assessment module, the specific method of determining the theoretical value of the gas flow and the gas flow leakage according to the real-time key parameters and determining the rotor wear assessment coefficient in combination with the real-time key parameters is: AS1: Obtain the real-time intake pressure, real-time exhaust pressure, real-time intake temperature, real-time exhaust temperature and real-time actual gas flow rate among the real-time key parameters, and mark them as: P in , P out , T in , T out , Q actual ; The theoretical value of gas flow Q is determined by the following formula theoretical : In the formula, k is the impact factor; AS2: Get the theoretical value Q of gas flow theoretical and the real-time actual gas flow Q actual , calculate the difference between the two and determine the gas flow leakage Q leak ; and the wear clearance area index A is determined by the following formula w ; In the formula, C d It is expressed as the flow coefficient, and ρ is expressed as the gas density; AS3: According to the law of energy conservation, the theoretical exhaust temperature T is determined by the following formula out,ideal : Where η is the compression efficiency; AS4: According to the wear clearance area index A w and theoretical exhaust temperature T out,ideal , the rotor wear assessment factor is determined by the following formula: Where W is the rotor wear assessment coefficient.

5. The air compressor remote fault diagnosis system according to claim 4, characterized in that: In the rotor clearance abnormality judgment module, the specific contents of receiving the real-time key parameters and obtaining the gas flow leakage in the rotor wear assessment module, determining the rotor clearance assessment value in combination with the rotor wear assessment coefficient, and judging whether the rotor clearance is abnormal according to the size of the rotor clearance assessment value include: Obtain the real-time intake pressure P among the real-time key parameters in , Real-time exhaust pressure P out , Real-time intake air temperature T in and gas flow leakage Q leak , combined with the rotor wear evaluation coefficient W, the rotor clearance evaluation value is determined by the following formula: Where, δ is the rotor clearance evaluation value; Compare the rotor clearance evaluation value δ with the threshold value G1: If δ>G1, it is judged that the rotor clearance is abnormal and the diagnostic information is generated; If δ≤G1, it is judged that the rotor clearance is abnormal and no treatment is performed; The threshold G1 is a preset value.

6. The air compressor remote fault diagnosis system according to claim 5, characterized in that: In the lubrication monitoring and diagnosis unit, the specific method of determining the lubrication evaluation coefficient according to the working parameters and determining whether to generate lubrication fault information according to the lubrication evaluation coefficient is: BS1: Obtain the lubricating oil pressure, lubricating oil temperature and lubricating oil flow rate in the working parameters, and record them as P o , T o and Q o ; BS2: Determine the lubrication pressure contribution factor L by the following formula: P : Where P ideal Expressed as the ideal lubrication pressure, σ P Expressed as the normal fluctuation range above and below the ideal lubrication pressure; The lubrication temperature contribution factor is determined by the following formula: Where, T ideal Expressed as the ideal lubrication temperature, σ T Expressed as the normal fluctuation range above and below the ideal lubrication temperature; The lubrication flow contribution factor is determined by the following formula: In the formula, Q ideal Expressed as ideal lubricating oil flow rate; BS3: Get the lubrication pressure contribution factor L P , Lubrication temperature contribution factor L T and lubrication flow contribution factor L Q , determine the lubrication evaluation factor L by the following formula: L=w1·L P +w2·L T +w3·L Q BS4: Lubrication evaluation coefficient L and threshold L thre For comparison: If L <L thre , it is determined that there is a problem with the lubrication coefficient and lubrication fault information is generated; no processing is performed in other cases; the threshold L thre is the default value.

7. The air compressor remote fault diagnosis system according to claim 6, characterized in that: In the normal operation diagnosis unit, the specific method of determining the working rotor clearance increment coefficient according to the working parameters and determining whether to generate the working operation clearance increase fault information according to the working rotor clearance increment coefficient is: CS1: Obtain the total operating time of the air compressor from the start of operation to the current moment, the real-time speed of the rotor at each moment, the difference between the input and output air pressures at each moment, and the real-time working temperature of the rotor at each moment, and record them as t, N(τ), ΔP(τ) and T(τ) respectively; CS2: The gap increment caused by cumulative wear is determined by the following formula: D wear (t)=∫0 t k w ·N(τ)·ΔP(τ)dτ In the formula, κ w is the wear coefficient of the rotor material, N(τ) is the speed at time τ; ΔP(τ): the difference between the input and output air pressures at time τ; CS3: The gap increase caused by thermal fatigue is determined by the following formula: D thermal (t)=∫0 t k t ·T(τ) n ·N(τ)dτ In the formula, κ t is the thermal expansion coefficient of the rotor material; T(τ) is the temperature at time τ; n is the exponent of the effect of temperature on thermal expansion; CS4: Combine the gap increment caused by cumulative wear and the gap increment caused by thermal fatigue to determine the working rotor gap increment coefficient ΔG(t): ΔG(t) = Δ wear (t)+Δ thermal (t); Compare the rotor clearance increment coefficient ΔG(t) with the rotor clearance evaluation value δ: If ΔG(t)≥δ, a fault message of increased working gap is generated; If ΔG(t)<δ, no processing is done.

8. The air compressor remote fault diagnosis system according to claim 1, characterized in that: Also includes: The remote management and maintenance module is used to receive the corresponding fault information generated by the diagnosis module, and arrange relevant maintenance personnel to perform on-site maintenance according to the generated corresponding fault information.

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