[求助] 求各位帮我看下这一组FROTAN帮我解答下（告诉下我什么意...

 SUBROUTINE TYPE534(TIME,XIN,OUT,T,DTDT,PAR,INFO,ICNTRL,*)

C-----------------------------------------------------------------------------------------------------------------------
C    DESCRIPTION:
C     THIS SUBROUTINE MODELS A VERTICAL CYLINDRICAL STORAGE TANK WITH AN IMMERSED
C     HEAT EXCHANGER. THIS ROUTINE SOLVES THE COUPLED DIFFERENTIAL EQUATIONS
C     IMPOSED BY CONSIDERING THE MASS IN THE STORAGE TANK AND THE MASS IN THE
C     HEAT EXCHANGER.
C  
C     NEW FEATURES:
C        - USERS CAN NOW SPECIFY THE FRACTION OF INLET FLOW THAT GOES TO EACH NODE
C        - LOSSES TO A GAS FLUE CAN NOW BE SPECIFIED (THESE LOSSES ARE SET TO ZERO
C            IF AUX ENERGY IS BEING ADDED TO THE TANK
C        - USERS CAN ADD/REMOVE ENERGY FROM ANY NODE BY THE USE OF "MISCELLANEOUS"
C            ENERGY FLOWS.  THIS FEATURE CAN BE USED TO SIMULATE A PILOT LIGHT.
C        - TEMPERATURE SEEKING MODE FOR THE FLUID INLETS HAS BEEN ADDED
C        - NEW NODAL EDGE LOSSES SO USERS CAN PARTIALLY BURY THEIR TANK ETC...
C        - MULTIPLE HEAT EXCHANGERS NOW ADDED
C
C     CARE SHOULD BE TAKEN WHEN CONSIDERING HIGH MASS FLOW RATES OF MIXING BETWEEN
C     NODES AS THIS CAN CAUSE AN ENERGY BALANCE PROBLEM WITH THE MODEL IF THE "CONVERGED"
C     PARAMETER IS TOO LARGE.
C     
C     UPDATES:
C        JULY 11TH, 2004 - FIXED A BUG WITH 1-NODE TANKS (FLOW_OUT_LOAD)
C        JULY 20TH, 2004 - FIXED A BUG WITH TANK VOLUME CALCULATION FOR HX REDUCTIONS
C        JULY 30TH, 2004 - REPLACED A FEW EXP( WITH DEXP(
C        SEPTEMBER 28TH, 2004 - ADDED THE ABILITY TO READ THE PARAMETERS FROM A DATA FILE SO WE CAN HAVE
C           A NICE APPLICATION PROGRAM THROUGH THE STUDIO
C        NOVEMBER 2, 2004 - FIXED A BUG IN THE TNK VOLUME CALCULATION FOR IHXGEOM=1
C        MARCH 25TH, 2005 - RESET THE NUMBER OF HX NODES TO ZERO FOR SYSTEMS WITHOUT A HX
C-----------------------------------------------------------------------------------------------------------------------
! Copyright ?2004 Thermal Energy System Specialists, LLC. All rights reserved.

C-----------------------------------------------------------------------------------------------------------------------
      !Export this subroutine for its use in external DLLs.
!DEC$ATTRIBUTES DLLEXPORT :: TYPE534
C-----------------------------------------------------------------------------------------------------------------------

C-----------------------------------------------------------------------------------------------------------------------
C    ACCESS TRNSYS FUNCTIONS

SUBROUTINE TYPE534(TIME,XIN,OUT,T,DTDT,PAR,INFO,ICNTRL,*)
!DEC$ATTRIBUTES DLLEXPORT :: TYPE534