Reliability assessment of mobile pumping units

An analytical formula for determining the mathematical expectation and variance is derived . functions reliability mobile pumping units, allowing evaluate residual development With taking into account their technical condition at the start of the next process. An analytical expression was determined For definitions mathematical expectations And differences V safe functions, which allows mobile pumping units to calculate the residual period at the beginning of the process taking into account its technical condition. The problem of trouble-free operation of mobile pumping units at any point in time taking into account their technical condition requires a new approach to assessing the level of reliability in order to ensure uninterrupted performance of the function as intended. Analysis of work in this area shows that to date their technical condition at the time of the start of operation is not taken into account. Therefore, when assessing the failure-free function, it is necessary to take into account that the mobile pumping unit at the time of its entry into operation has some random operating time “ η ” , preceding the moment of the start of the next operation. In other words, the mobile pumping unit begins to function with varying degrees of risk of failure. The above indicates the need to conduct a calculation assessment of the level of failure-free operation of mobile pumping units before its operation. The importance of assessing the random time of a mobile pumping unit , taking into account some developed random operating time, dictates the need to develop new calculation models for their definition. Below is a mathematical formulation and solution to this problem. According to the obtained results of the statistical study, the type of the considered probability function of failure-free operation of the mobile pumping unit obeys the Weibull distribution law. Then the probability of failure-free operation is expressed as a pump that has worked without failure for a time, according to the stated requirement, will still function for u time, i.e. until the moment of time , characterizing the moment of failure. Then, the probability of this event, according to the definition of the conditional distribution function /1/: the average time before failure, under the condition we denote by .