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Re: [EnergyPlus_Support] Re: BMS (Building nergy management system )





 
Timestep in IDF for simulation is the number of steps in one hour.  timesteps of 6 means in 10 mins interval.
 
Timestep in a report may mean the requested reporting interval.  Because it is a rate value, the interval is not important.
 
Hourly, daily, monthly, annual values are all averaged.  If you do not run a simulation for a period longer than one month, there would be no monthly report.
 
If the program was not run successfully,  there would not be any report.
 
If the boiler is turned off in Summer, there would be no monthly boiler consumption values for the Summer months
 
sory i know the meaning of TIME STEP , but i dn't know the meaning of TIMESTAMP ,
 
Boiler and hot water tank is the source to feed the water coil in a HVAC system.  The air that flows through the coil is used to heat a zone.  This air may be mixed with fresh outdoor air, and the return air may be recycled through the system to save energy of heating the zone
in this building i dnt have water coil in a HVAC system , i use boiler and water tank to simulate radiator that there is only water .
in radiator we dnt have return air and supply air  we only use return water and supply water .
 
thanks
 
 

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Sunday, December 18, 2011 11:02 PM
Subject: RE: [EnergyPlus_Support] Re: BMS (Building nergy management system )

 
Sorry, if I have offended you in my last reply.
 
I am not a member of the design team, but another user as you are.  The only difference is that I know the real hardware well and can structire the EPlus objects to match a system.  And I have scan through the EPlus Ver 3.0 manuals, cover to cover.  I can follow what is in the EMS programming
=======================
 
 
Before you want to use a compact schedule,  setpoint, node temperature, control, manager, etc. you must under stand their functions.
 
Before you have complete a building system simulation and let the program know what you want to see, there is nothing to report.
 
BMS is a general name for people who wanted to have information to be used in a LEED certificate or similar document. 
 
My other comments are continued in your e-mail below.
============================================
You are not the only one or first one to ask questions like this.  90% of user in this group expect to see a monthly report on the first simulation run.
 
If a user has work through a few examples and study the output values on a spread sheet, it would enable him to determine that his own program is running or not.  The outdoor dry bulb temperatue, zone mean air temperature, daytype index, and  schedule values should be displayed.  Some diagnostic should be turned on.
 
There is a whole list of available variables in the .rdd file (Report Data Dictionary)  If you do not ask for it, it will not be generated.  Similary, if you do not ask for the report variables, they will not be generated.
 
 Dr. Li  

 
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Sun, 18 Dec 2011 15:40:18 +0000
Subject: RE: [EnergyPlus_Support] Re: BMS (Building nergy management system )

 
Thanks for your quickly answering
 
sorry i most model the plant of building that has a hot water boiler and water heater so in this plant there is no aircoil  and other system that releated to air system , so i think maybe for this plant that only have water system i should use compact schedule that determine the water temperature of node?
 
Boiler and hot water tank is the source to feed the water coil in a HVAC system.  The air that flows through the coil is used to heat a zone.  This air may be mixed with fresh outdoor air, and the return air may be recycled through the system to save energy of heating the zone.
 
Air system is the final usage of the heat from the boiler.  EPlus does not really simulate the boiler and the thank.  It calculates the heat demand and matchit with the plant supply.
 
If you want to set the tank to 80°C, you use the set point in the hotwater loop objects.  You can turn the plant on and off  with a fixed schedule for a one year period.  Compact schedule is a short cut to the year schedule, month sehedule, week schedule, and day schedule, which has 12 day types. The compact schedule is expanded to this full schedule in the program.
 
Up to two or three years ago, the schedule cannot be changed with the current outdoor wheather condition.  Now using the advanced availabilioty and setpoint manager and controls, the schedule value can be changedin the IDF.  Using more advanced EMS (erl) file, note values not directly alterable may be customized using this tool.
 
After you have set the tank temperature to a setpoint value, the EPlus would turn on the heater and monitor this temperature and maintain it to that temperature.
 
sorry i have problem  with summary output report : in monthly report for boiler " BOILER GAS  CONSUMPTION RATE {TIMESTAMP}" what is the meaning of timestamp ?and how monthly report calculate ?it 's average of whole month ?
 
Timestep in IDF for simulation is the number of steps in one hour.  timesteps of 6 means in 10 mins interval.
 
Timestep in a report may mean the requested reporting interval.  Because it is a rate value, the interval is not important.
 
Hourly, daily, monthly, annual values are all averaged.  If you do not run a simulation for a period longer than one month, there would be no monthly report.
 
If the program was not run successfully,  there would not be any report.
 
If the boiler is turned off in Summer, there would be no monthly boiler consumption values for the Summer months.
 
 
thanks
 





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