Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Following the previous answer by Julien Marrec I tried the following:
I used the example file "CoolingTower_TwoSpeed" Run period 01/05 to 20/05 and Weather file "USA_CA_San.Francisco.Intl.AP.724940_TMY3.epw" I created a model with EMS called "CoolingTower_TwoSpeed_EMS" I added a sensor using the variable "Plant Supply Side Cooling Demand Rate" with the name "PSSCDR" I added an actuator on the pump variable "Pump Mass Flow Rate" with the name "PMFR" I added a simple program with the line "set PMFR=PSSCDR/4180/5+1.1*0.025"
Note that it is a very rough control: I used a fixed temperature difference of 5 degrees. The main problem is that with this method the plant temperatures are getting too hot during the warm-up and you will get an error. Therefore I added a constant value equal to the 2.5% of the design pump mass flow rate (1.1 kg/s).
I obtained: -21.88% pump energy consumption and -1% in cooling energy consumption (beacause the chiller condensed inlet temperature is lower in the EMS case). The energy saving is related to this specific example.
| | 2 | No.2 Revision |
Following the previous answer by Julien Marrec I tried the following:
Note that it is a very rough control: I used a fixed temperature difference of 5 degrees. The main problem is that with this method the plant temperatures are getting too hot during the warm-up and you will get an error. Therefore I added a constant value equal to the 2.5% of the design pump mass flow rate (1.1 kg/s). kg/s): it solved the temperatures error in my case.
I obtained: -21.88% pump energy consumption and -1% in cooling energy consumption (beacause the chiller condensed inlet temperature is lower in the EMS case). The energy saving is related to this specific example.
