|
Boundary conditions for elementary functions of probability densities for the production process rea |
|
|
|
|
Boundary conditions for elementary functions of probability densities for the production process realised in longwalls Author: R. Snopkowski
Fundamental criterion for assessment of the efficiency of production process realised in a longwall is the lack of breaks in work of mining machine (except breaks which result from the technology applied or operation schedule). Rated outputs for machines which are used in longwalls are high enough so that only other reasons can cause that it is impossible to make full use of these machines. Among these reasons can be listed e.g. geology-mining conditions which occur in the studied longwall (Sikora, 1991). The author undertook the study in which numerical model of production process which is carried out in the longwall was used. The model was described in (Snopkowski, 2000). In this model, it is assumed that time periods for realisation of activities and operations realised in the longwall, which influence the advance of the heading machine, are given in the form of elementary functions of probability densities. The term "elementary" was proposed by the author in order to differentiate these functions from other functions and because these functions describe realisation time in units [minute/meter]. The model is a simulation model (software written in FORTRAN) and it enables to fully reflect of the actual run of the production process with keeping the rules which result from the technology which is used. In three samples of calculations, different relations between elementary functions of probability densities were assumed. Those assumptions resulted from different geology-mining conditions which occured in longwalls. The influence of those relations on time of the production cycle was determined. The total time of heading machine breaks during "mining" along the whole longwall length was registered. On the base of calculations which were performed, the following boundary conditions for elementary functions of probability densities were suggested [(5) p.509].
|
2009