DOE-2 Reference Manual Version 2.1 - DOE2.com

Rules:1. Table V.11 illustrates the default hierarchy of temperatures of recoverableheat. Recoverable heat from equipment or processes in the supplycolumn can be directed to the equipment or processes in the demandcolumn, which are at a lower temperature. The effectiveness of theexchange is either specified by the appropriate PLANT-PARAMETER keywordor the heat exchanger is assumed to be large enough to exchange therecoverable heat. The user should not specify a demand if the stratum ofthe demand is greater than the supply stratum; however, the user may doso, if the Second Law of Thermodynamics is not violated. A warning willbe issued when this default hierarchy is overridden.For example, the specificationHEAT-RECOVERYSUPPLY-1 = (STURB-GEN)DEMAND-1 = (ABSORI-CHLR)will issue a warning because the 102°F exhaust temperature for a steamturbine (see the STURB-EXH-PRES keyword in the PLANT-PARAMETERS instruction)is insufficient to fire a single-stage absorption refrigerationunit requiring a minimum of 180°F. If, however, STURB-EXH-PRES isspecified so that a 200°F exhaust temperature will be achieved, thewarning can be ignored.2. Rule 1 applies only to supplies and demands at the same priority level.There is no restriction that the supply at level 1 be at a higher temperaturethan the supply at level 2. The SUPPLY-I, DEMAND-1 keyword pairmerely tells the PLANT simulation to treat that heat recovery operationbefore treating the heat recovery operation described in the SUPPLY-2,DEMAND-2 keyword pair.3. If the supply exceeds demand at a given level, the demand is satisfiedand the remaining available recoverable heat is rejected, unless eitherthis supply equipment is respecified at a lower level or the supplyingprocess is solar (SOL-SPACE-HEAT, SOL-PROCESS-HEAT, or SOL-COOLING). Thesolar source is assumed to be a storage tank that is left partiallycharged after meeting the demand. Excess demand from a level is met bythe conventional PLANT heating equipment. Each equipment and process canbe entered on as many levels (up to 5) as the user desires, and, withinthe restrictions of Tables V.9 and V.10, can be entered as both supplyand demand.Example:HEAT-RECOVER YSUPPLY-1DEMAND-1 =SUPPLY-2 =DEMAND-2(DIESEL-JACKET)(ABSOR1-CHLR)(DBUN-CHLR, DIESEL-JACKET)(SPACE-HEAT, PROCESS-HEAT)V.58 (Revised 5/81)