CN111456932A - Event importance analysis method in compressor fault process - Google Patents

Abstract

The invention discloses a method for analyzing the importance of events in a compressor failure process, which is characterized in that the process is represented by a network structure according to the compressor failure process to form a compressor failure network; The importance of binary structure and probability structure are considered. Considering the difference between the compressor fault network system and the compressor fault, it is further divided into the importance of the fault initiation event to the network structure and the importance of the compressor fault structure. The structural importance of the failure initiation event can be used to deal with important failures in the compressor failure process under the condition of limited resources to ensure the normal operation of the compressor.

Description

A method for analyzing the importance of events in the process of compressor failure

technical field

The invention relates to the safety of the production process, in particular to the processing of important faults in the compressor failure process under the condition of limited resources, so as to ensure the normal operation of the compressor.

Background technique

Any failure or disaster, including natural system disasters and artificial system failures, does not occur suddenly, but an evolutionary process. This evolutionary process is affected by many factors, showing diversity; many events occur in sequence according to a certain logical relationship and have a network connection structure. It can be seen that the focus of studying the fault evolution process is the interference of different factors to the process and the logical relationship between the events in the process. The same goes for compressor systems. Compressors are commonly used equipment in the industrial production process. Although the types of compression molding machines are different, the basic working principle is the same. Therefore, the working process of the compressor, various events that may occur in the process, the devices included in the events, and the operating states of the devices have certain similarities for different compressors. Similarly, because of the similarity of the above-mentioned processes, events, devices, and states, the failure processes of different compressors have similarities. Therefore, a compressor failure process analysis method can be established by analyzing the compressor failure process, and the logical relationship between each failure event and the compressor failure event in the failure process can be determined. Determine the importance of each failure event in the process of compressor failure, and then get the importance order. In the case of limited resources, the important faults in the compressor fault process are dealt with, so as to ensure the normal operation of the compressor.

SUMMARY OF THE INVENTION

A method for analyzing the importance of events in a compressor failure process is characterized in that the process is represented by a network structure according to the compressor failure process to form a compressor failure network; considering the state transition of the failure initiation event, a binary structure is proposed Importance and probability structure importance; considering the difference between the compressor fault network system and the compressor fault, it is further divided into the importance of the fault initiation event to the network structure and the importance of the compressor fault structure; calculate these four fault initiation events Structural importance can be used to deal with important faults in the process of compressor failure under the condition of limited resources to ensure the normal operation of the compressor.

A method for analyzing the importance of events in a compressor fault process according to claim 1, wherein the events included in the compressor fault network, and the objects and states in the events are as shown in the following table:

The event importance analysis provided by the method is based on these events, objects and states.

A method for analyzing the importance of events in a compressor failure process according to claim 1, wherein the compressor failure network is formed according to the events included in the compressor failure network, and the objects and states in the events, and further the compressor failure network is formed. The machine fault tree is used to calculate the importance of four structures.

Definition 1. Binary structure importance BSI: In the fault network, each fault event does not consider the probability of occurrence or assumes that the probability of occurrence is the same, and the event state is two kinds of 0 or 1, and the transition probability of these two states is the same as 1/2 , the importance of the fault initiating event in the network; the structural importance is subdivided into the importance of the fault initiating event to the network structure and the importance of the compressor fault structure.

Definition 2. The importance degree of network structure of fault initiation event EEN: In the binary structure importance, the degree of fault network state change caused by the state change of fault initiation event. The meta structure is abbreviated as EENB, as shown in formula (1).

表示“或”关系同级故障起始事件个数多个1/2相加；

表示“与”关系同级故障起始事件个数多个1/2相乘；TE_j表示网络中的压缩机故障事件；↓表示从TE_j逐级向下按照

进行计算；

表示网络中故障起始事件EE_i对压缩机故障事件TE_j的二元结构重要度的和。where:

Indicates that the "or" relationship is the addition of 1/2 of the number of fault initiation events at the same level;

Indicates that the "AND" relationship is multiplied by 1/2 of the number of fault initiation events at the same level; TE _j represents the compressor fault events in the network; ↓ means _that the

Calculation;

It represents the sum of the binary structure importance of the fault initiation event EE _i to the compressor fault event TE _j in the network.

Definition 3. Fault Initiation Event Compressor Fault Event Structural Importance EET: In the binary structure importance, the degree of state change of a compressor fault event in the network brought about by the state change of the fault initiating event, in the binary structure Abbreviated as EETB, as shown in formula (2).

Definition 4. Probabilistic structure importance PSI: In the fault network, when the probability importance of each fault initiation event is considered, the importance of the fault initiation event in the compressor fault network.

The network structure importance EENP of the fault initiation event in the probability structure is shown in formula (3).

In the formula: jj represents all the fault initiating events from TE _j to the downward level, and there is an AND-or relationship between these fault initiating events;

In the probability structure, the failure initiation event compressor failure event structure importance is EETP, as shown in formula (4).

Description of drawings

Figure 1 Evolution process description and transformation

Figure 2. Hierarchical diagram of system fault evolution process

Detailed ways

The first-stage failure process of a three-stage reciprocating compressor is studied. The compressor fault process is described according to the actual situation, and the events, objects and states can be obtained as shown in Table 1, and the compressor fault process is shown in Figure 1.

Table 1 Node analysis of evolution process

Figure 1 is intended to illustrate the situation in which a causal event "ANDs" during a compressor failure leads to a consequent event, such as V ₁₀ . Convert Figure 1 into a tree structure with 5 levels, as shown in Figure 2. The arrow line in Fig. 1 and Fig. 2 indicates the development direction of the fault, from the cause event to the result event.

T in the figure represents the entire compressor failure process system. During the process, _one of V2, _V10 or _V15 fails and the compressor fails, so their relationship to the system is "OR". The "+, ·" in the subscript of the event in the node respectively represent the logical "OR, AND" relationship between the lower-level event and the current-level event. The EENB and EETB in the binary structure are calculated according to definitions 1, 2, 3, as shown in Table 2.

Table 2 EENB and EETB for different edge events

It can be seen from Table 2 that in the compressor fault process, the structural importance of each fault initiation event to the compressor fault network is ranked as follows: V ₈ >V ₁₁ =V ₁₃ >V ₁₄ >V ₃ =V ₄ =V ₆ =V ₇ >V ₁₆ >V ₁ . According to definition 4 and equations (4), (5), EENP and EETP are calculated, as shown in Table 3. where p represents the probability of occurrence of the corresponding event.

Table 3 EENP and EETP in the probability structure

Figure 2 is a two-state representation of events, i.e. 0,1 states, each with a 50% probability of occurrence. Each event has a corresponding failure probability p. Then the failure probability of the corresponding event is brought into Table 3 to obtain the structural importance of each failure initiation event. With the help of the above method, the structural importance of fault initiating events in the case of two states and the structural importance of fault initiating events in the case of probability can be obtained.

Compared with the existing method, it has the advantage that the causal relationship between each failure time in the compressor failure process can be analyzed, and the importance of the failure event under the complex network relationship can be obtained, so as to efficiently determine the key failure events in the compressor maintenance process.

Claims (3)

1. A method for analyzing event importance in a compressor failure process is characterized in that the process is expressed by using a network structure according to the compressor failure process to form a compressor failure network; considering the state conversion of the fault initial event, providing the importance of a binary structure and the importance of a probability structure; considering the difference between a compressor fault network system and a compressor fault, further dividing the fault initial event into the importance degree of the fault initial event to a network structure and the importance degree of the fault initial event to the compressor; the structural importance of the four fault starting events is calculated, and the method can be used for processing important faults in the fault process of the compressor under the condition of limited resources and guaranteeing the normal operation of the compressor.

2. The method for analyzing the importance of the event during the failure process of the compressor according to claim 1, wherein the event contained in the failure network of the compressor, and the object and the state in the event are shown in the following table,

the event significance analysis provided by the method is based on these events, objects and states.

3. The method for analyzing the importance of the events in the compressor failure process according to claim 1, wherein a compressor failure network is formed according to the events contained in the compressor failure network and the objects and states in the events, a compressor failure tree is further formed, and four structural importance degrees are calculated;

definition 1 binary structural importance BSI: in the fault network, the importance of the fault starting event in the network is determined when the occurrence probability of each fault event is not considered or assumed to be the same, the event states are two kinds of 0 or 1, and the transition probabilities of the two kinds of states are the same as 1/2; the structural importance is subdivided into the importance of the fault starting event to the network structure and the importance of the fault structure to the compressor;

define 2 failure initiation event network fabric importance EEN: in the significance of the binary structure, the degree of the fault network state change caused by the fault initiation event state change, the network system state change refers to the compressor fault event state change, which is abbreviated as EENB in the binary structure, as shown in formula (1),

in the formula:

a plurality 1/2 of fault initiation events representing "OR" relational peers added;

a multiplication of 1/2 representing the number of peer fault initiating events in the and relationship; TE_jIndicating a compressor failure event in the network; ↓ represents slave TE_jStep by step downward according to

Calculating;

representing a failure initiation event EE in a network_iFor compressor failure event TE_jThe sum of the binary structural importance of (a);

define 3 failure onset event compressor failure event structural importance EET: the degree of a change in the state of a compressor fault event in the network, resulting from a change in the state of the fault initiation event, in a binary structure, abbreviated as EETB, is important as shown in equation (2),

defining 4 probability structure importance PSI: in the fault network, when the probability importance of each fault initial event is considered, the importance of the fault initial event in the compressor fault network;

the network structure importance of the fault initiation event in the probability structure, EENP, is shown as formula (3);

in the formula: jj denotes slave TE_jAll fault starting events which are expanded downwards step by step, and an AND-OR relation exists among the fault starting events;

the structural importance of the compressor failure event is EETP, the failure onset event in the probabilistic structure, as shown in equation (4).

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