DOE-2 Reference Manual Version 2.1 - DOE2.com

(-EIR-FT)(-EIR-FPLR)Elec inFor the given equipment, the electric input ratio correctionfactor (ratio of electric input to nominal capacity) is abi-linear or bi-quadratic function of the exiting chilledwater temperature and the entering condenser watertemperature.For the given equipment, the electric input ratio at fullload will be multiplied by a linear or quadratic functionof the part-load ratio to obtain the electric input to theequipment at part load. The calculation will look likethis:EIRfull_load x (a + bPLR + CPLR 2 ) x( -EIR-FT) x SIZE x (-CAP-FT).It is important to note that the -FPLR functions are allmultiplied by the available capacity, not the load. Thismeans that the ratio of load to capacity (part load ratio,PLR) is embedded within these functions. Since thedefinition of COP is usually the ratio of load to energyinput, the ratio of COP at full load to that at the actualload would have to be multiplied by the part load ratio toproduce the -FPLR function.loadPLR * Size * (-CAP-FT)= COP(load} COP full load * COP(PLR} * COP(T)where COP{PLR) and COP{T) are modifier functions for partload and temperature.Relating the two equations for Elecin, it can be seen that(-EIR-FPLR)PLRCOP(PLR}(-HIR-FT)(-HIR-FPLR)Therefore, to input a constant efficiency unit, data points(O,O) and (1,1) or coefficients (0,1) should be inputthrough the CURVE-FIT command. Note that the use of datapoints (0,1) and (1,1) or coefficients (1,0) does notrepresent a constant efficiency unit.This is like -EIR-FT except that, instead of the electricinput ratio, the heat input ratio correction factor will befound. (This form is used with absorption chillers.)This is like -EIR-FPLR except that instead of the electricinput ratio the heat input ratio correction factor will befound. (This form is used with absorption chillers.)V.39 (Revised 5/81)