DOE-2 Reference Manual Version 2.1 - DOE2.com

10. SYSTEM-FLUIDThe function of the SYSTEM-FLUID instruction is to provide informationthat is applicable specifically to the hydronic part of two pipe induction andheat pump systems. This subcommand is appropriate only to the TPIU and HPsystems. Several SYSTEM-FLUID instructions may be entered if the facility isserved by more than one mixed air-water system and/or it is desired to conductparametric runs.SYSTEM-FLUID is a "subcommand" of SYSTEM and, as such, can be used toinput a subset of data to SYSTEM.An alternative mode for data entry is to complete and enter SYSTEM-FLUIDkeywords and their values directly into the SYSTEM command (if this approachis chosen, omit the SYSTEM-FLUID keyword in SYSTEM).Note that pumping horsepower is accounted for by the PLANT Program, ratherthan the SYSTEMS Program. The calculations of pumping energy are based on thedefault value for plant constants HCIRC-IMPELLER-E, HCIRC-MOTOR-EFF,HCIRC-HEAD, and HCIRC-DESIGN-T-D (heating), CCIRC-IMPELLER-E, CCIRC-MOTOR-EFF,CCIRC-HEAD, and CCIRC-DESIGN-T-D (cooling), and, if SYSTEM-TYPE ~ HP or TPIU,TWR-MOTOR-EFF, TWR-IMPELLER-EFF, and TWR-PUMP-HEAD (cooling tower). Thesedefault values can be changed for any run using the PLANT-PARAMETERSinstruction (see Chap. V).SYSTEM-FLUIDINDUC-MODE-SCHMIN-FLUID-Tinforms the SDL Processor that the data to follow are relatedto the hydronic part of air-water type systems. A uniqueuser-defined name must be entered in the U-name field of eachSYSTEM-FLUID instruction. Omission of this entry in the"subcommand" will cause an error.specifies the U-name of a SCHEDULE that defines the mode ofthe coils in the terminal induction unit for a two-pipeinduction system (TPIU). If the hour's SCHEDULE value ispositive, all zone coils can provide cooling only. If thehour's SCHEDULE value is negative, all zone coils can provideheating only. Additionally, if the value is negative (zoneheating) and COOL-CONTROL is not equal to CONSTANT, theprimary air controller set point temperature is reset toMIN-SUPPLY-T (thus ensuring a cooling source in addition to aheating source).When the unitary heat pump system (HP) is being simulated,the input for this keyword is the minimum allowable temperature(entering the heat pumps) for the circulating heataddition/heat extraction fluid. The program simulatesaddition of heat, as required, to prevent fluid temperaturefrom falling below this value. The heat addition componentis specified in a PDL instruction for the PLANT Program andis simulated by the PLANT Program (see Chap. V).IV.234 (Revised 5/81)