Chiller plant simulation software how to#
Chiller plant simulation software full#
Chiller plant simulation software Pc#

ChillerCyclingRatio is an available output from the visualizer and if more information on the ChillerCyclingRatio is desired the user may view the EnergyPlus Engineering Reference document.

Chiller plant simulation software Pc#

Pc h iller = C h iller Compressor PowerВ (Watts)Д¬OPref = Reference Coefficient of Performane ( W/ W )Д¬ h illerEIRFTemp = energy input to cooling output factor, see Ambient Relief CurveД¬ h illerEIRFPLR = energy input to cooling output factor, see Power CurveД¬ h illerCyclingRatio = less than 1.0 when chiller PLR is less than min PLRДЄll of the above variables have been discussed within this document except ChillerCyclingRatio. Pc h iller =( Qavail )( 1/ COPref )( C h illerEIRFTemp )( C h illerEIRFPLR )( C h illerCyclingRatio ) The below equations to calculate chiller power at a given time step are based on the EnergyPlus Electric Chiller Model Based on Condenser Entering Temperature.

This output can be confirmed in the visualizer:

Looking in the visualizer the cooling load was the below, which also needs to be converted to watts: The PLR can then be calculated after the actual cooling load at the time step is known, which can be found in the visualizer. Q ref = chiller capacity at reference conditions (W) Qavail = available c h iller capacity adjusted for current fluid temperatures W The Qref must also be converted from tons to watts: In order to find the PLR the available cooling capacity first needs to be calculated. X = PLR = part-load ratio = (cooling load) / (chillerвЂ™s available cooling capacity)Д¬hillerEIRFPLR = Energy input to cooling output factor (Equal to 1 at reference conditions)

Chiller plant simulation software full#

It also shows that at the intersection of the design leaving chilled water temperature of 44 deg F and the reference entering condenser water temperature of 85 deg F the Full Capacity % equals 100%.Д¬ 1 to C 4 = coefficients, where C 4 is used only in the cubic equation. If the leaving chilled water temperature remains constant, but the condenser temperature increases that would be an increase in lift. Lift is defined as the difference in operating pressure between the condenser and evaporator. It shows that during lower lift conditions the Full Capacity % is greater and as the lift is increasing the Full Capacity % decreases. This example shows a pretty typical capacity curve set for a chiller. To view the curves associated with the chiller used in the simulation the user will need to enter the equipment library, for this example the curves are shown below.

Chiller plant simulation software how to#

If it is of interest to the user to create custom chiller curves please refer to the answer on How to Use the Curve Wizard. There are three different curve types that work in conjunction to calculate chiller energy. This is where the user will also have to specify the Time Frequency in which they would like to view the data, which could be Monthly, Daily, Hourly, Run Period, or at the Time Step. Make sure to select Cooling Plant as one of the output variables. If the user is unaware of how to use the Visualizer please see this link. The best place to view chiller energy throughout the simulation period is in the Visualizer. The other section of this document is a sample scenario that will go into more detail on the chiller curves and how TRACE calculates chiller energy. If the user would just like to see where to find chiller energy please refer to the Visualizer section. The EnergyPlus models can be read about in further detail in the EnergyPlus Engineering Reference document, see sections 14.3.9 and 14.3.10. Detailed Water Cooled chillers are based on the Condenser Leaving Temperature. Simple Water Cooled and Air Cooled chillers will be based on the Condenser Entering Temperature.

Electric Chiller Model Based on Condenser Leaving Temperature.

Electric Chiller Model Based on Condenser Entering Temperature.

The calculations for determining water or air cooled chiller energy are based on the EnergyPlus models