Error when autosizing the load for cooling tower
When autosizing the load for cooling tower by E+, the warnings below were raised:
** Warning ** Error when autosizing the load for cooling tower = SINGLESPEED COOLING TOWER 2. Tower Design Range Temperature is different from the Design Loop Delta Temperature.
** ~~~ ** Tower Design Range Temperature specified in tower = SINGLESPEED COOLING TOWER 2
** ~~~ ** is inconsistent with Design Loop Delta Temperature specified in Sizing:Plant object = CONDENSER LOOP.
** ~~~ ** ..The Design Range Temperature specified in tower is = 4.00
** ~~~ ** ..The Design Loop Delta Temperature specified in plant sizing data is = 5.00
** Warning ** Error when autosizing the UA for cooling tower = SINGLESPEED COOLING TOWER 2. Tower Design Approach Temperature is inconsistent with Approach from Plant Sizing Data.
** ~~~ ** The Design Approach Temperature from inputs specified in Sizing:Plant object = CONDENSER LOOP
** ~~~ ** is inconsistent with Design Approach Temperature specified in tower = SINGLESPEED COOLING TOWER 2.
** ~~~ ** ..The Design Approach Temperature from inputs specified is = 2.00
** ~~~ ** ..The Design Approach Temperature specified in tower is = 4.00
For the 1st warning, translate error from OpenStudio osm file was suspected as
In osm:
4, !- Design Approach Temperature {deltaC}
**5, !- Design Range Temperature {deltaC}**
In idf translated from osm:
4, !- Design Approach Temperature {deltaC}
**4, !- Design Range Temperature {deltaC}**
For such error, I think maybe it should be fixed by OpenStudio.
For the 2nd warning, no clue was found.
Have anyone encountered similar warnings?
My soft versions:
OpenStudio App: 1.7.2
OpenStudio: 3.7.0
EnergyPlus: 23.2
I found the reason for the 2nd warning. The design approach temperature is the difference between the temperature of the water leaving the cooling tower (set by Design Loop Exit Temperature in Sizing:Plant) and the wet bulb temperature of the air entering the tower (set by Design Inlet Air Wet-Bulb Temperature in CoolingTower:SingleSpeed). Design Approach Temperature should equal (Design Loop Exit Temperature - Design Inlet Air Wet-Bulb Temperature). Correct these parameters will avoid the 2nd warning.