Page 465 - Advanced Mine Ventilation

434 Appendix B: Ventilation Network Analyzer in Fortran IV

hand, the number of branches and junctions with diesel exhaust sources are treated as
branches and junctions with special diesel exhaust emission rates. The last two vari-
ables on line 405, viz., NQDBS and NQDJS, are the number of such branches and
junctions, respectively, in the network. The general exhaust emission rates can be
only read in as bulk flow in cubic feet per minute for junctions, but for a branch it
can be read in either as bulk flow or incremental flow, e.g., cfm/ft. of the roadway.
In any case, the bulk flow is always calculated and stored in the arrays QDWALL(I)
and QDJUNC(I) for branches and junctions, respectively.
Lines 414e438 handles all the branches and junctions which are not covered by the
general case. From line 416 to 419, special diesel exhaust emissions are read in for in-
dividual branches and stored in the array QDWALL(I). Those lines are skipped if
NQDBS is zero. As with the previous case, the special diesel exhaust emission for a
branch can be read in as a bulk flow or as incremental flow over the entire length of
the roadway. From line 421 to 428, special diesel exhaust emissions at particular junc-
tions are read in and stored in QDJUNC(I). Those lines are skipped if NQDJS is zero at
line 420. Lines 423e424 determine the junction counter number corresponding to
junction no. II. As mentioned before, QDJUNC(I) is the quantity of diesel exhaust
flow available at junction number 1.
Lines 429e437 are labelled as roadway calculations. They add the diesel exhaust
emitted in each roadway to the total diesel exhaust flowing into that roadway. They
also contain operations which determine the branches having flow away from a given
junction. When line 429 is entered for the first time, the starting junction is the outside
junction counter number, JJ. The next four lines determine the branch number I, hav-
ing flow away from the junction JJ. For the first pass through the “ROADWAY
CALCULATION” section, these branches will be all the roadways leading into the
mine from the surface. Line 434 adds diesel exhaust emission in the roadway (equation
[3.55]) and line 435 determines the concentration (equation [5.8]). Line 436 marks
these branches (in the array MB) with a 1, indicating that calculations for them are
completed. Control is now passed to the section called junction calculations.
Lines 438e457determine the concentration of diesel exhaust at the junctions from
the air and diesel exhaust flowing into that junction. In order to do this, a junction must
be known where all these quantities are known. Starting on line 438, a search begins
through all the junctions using the junction counter number. If the junction has already
been processed, then that junction is bypassed (line 439).
Lines 440e447 determine the branch number J with inflow to the junction having
counter no. I. If any of these in flowing roadways has not been processed, that is the
diesel exhaust concentration in that roadway is not known (MB[J] is marked with a
zero), then that junction is bypassed. If the diesel exhaust concentration for all the
inflowing roadways are known, the total diesel exhaust flow at the junction
(Eq. 5.9) and total air flow at the junction (Eq. 5.10) can be determined. This is accom-
plished on lines 448, 449, 452. On line 454, the diesel exhaust concentration at
junction I is determined (Eq. 5.11) and this junction is marked with 1 on the next
line, At this point, the control is passed back to line 429. The junction where diesel
exhaust concentration was just found is now the new starting junction (line 451