Assessment of the reliability оf operation of water purification system units in transitional modes

Abstract

Ensuring uninterrupted and reliable operation of water treatment systems is a priority task of the industrial complex of Ukraine. For effective reliability management in water treatment systems, it is necessary to analyze potential failures and determine the probability of their occurrence. For the purpose of research to determine the probability of the occurrence of risks as a result of failures of various units of the water purification system, using the example of the operation of a column-type electrocoagulator, it is proposed to use the structural and functional block diagram of water purification systems to obtain generalized patterns, which makes it possible to reduce the entire system to several interdependent units, namely: 1) fine-cleaning filtration unit; 2) a unit for cleaning from soluble impurities; 3) a unit for cleaning coarse impurities; 4) pipe-pump unit. When the water treatment system is operating, taking into account the ranking of the reliability of the units, it can be stated that the 1st unit may fail at the beginning, followed by the 2nd, 3rd and 4th units. It is established that if all the units of the system are working, the system is in the S0 state. When other blocks fail, in the same sequence, the system will be in states S1, S2, S3 and S4. The most interesting are the states of the system, in which block failures do not cause shutdown of the entire system, but only its off-duty operation, which is manifested only as a result of the deterioration of the quality of treated water. Analyzing the obtained results, it can be asserted that during the operation of the water treatment system, the highest probability of failure is in unit 1. After the unit is restored and during further operation of the system, the highest probability of failure is unit 2, then unit 4 and unit 3. The failure probabilities of the units are the probabilities of risks, moreover, the physical value generated by these risks (the amount of polluted water that entered the ecosystem or the boiler unit) will be greater, the longer the unit failure detection period. When the water treatment system operates for a long enough time, a probabilistic constant mode of transition from state to state is established in it according to the scheme «working state of all blocks - failure of one or several blocks - repair - working state of all blocks». The probability of the sequence and duration of these events can be determined, which makes it possible, on the one hand, to assess the risks arising during operation and to determine a management strategy to minimize these risks.