Determine boiler temperature performance KPI score

Applicable Systems

• Primary: BLR

Objective/Method/Outcome

• Objective: Determine boiler temperature performance score

• Method: Analyze the daily performance metric based on the total time the HWST is within the deadband while the unit is on.

• Outcome: A KPI score is generated on a daily basis while a ‘Bad Score’ insight is produced if the weekly KPI score is lower than a threshold (default 60%).

Logic

• Input normalized hot water supply temperature and its corresponding temperature set points.
• With a temperature setpoint deadband constant, check if the deviation is out of acceptable range.
• If threshold is exceeded and the building is active, pass the hourly score.
• Aggregate samples into a daily and weekly score; generate the daily KPI score in a CTL.
• If weekly score exceeds acceptable weekly threshold, generate an insight. Note: the user must change the trigger block to “Insight – Bad Score”.

while(occ == 1)
   {
   if( |HWST - HWST SP| > Deadband Const. )
         {
         Award performance KPI score 0%
         }
   else
         {
         Award performance KPI score 100%
         }
   average performance KPI score daily
   average performance KPI score weekly
   }

Determine boiler temperature performance KPI score

Description / Method

Determine the performance index of a hot water supply temperature (HWST) control system using the amount of time the hot water supply temp is within the deadband (SP ± 3)while the unit is on. {BLR | heatexchanger}

Diagnosis / Recommended Action

1. Issue with control loop. Review and modify controller tuning parameters.
2. Heating water not available. Verify boiler plant operation.
3. Automatic setpoint control has been overridden. Revert setpoint back to automatic control.
4. Input sensor(s) faulty or miscalibrated. Verify input sensor(s) operation.

Message

The boiler’s hot water supply temperature KPI score is below 60% for the week. Review control loop tuning parameters.

Notes

This rule will not generate an insight unless the user changes the Trigger Block to “Insight – Bad Score”.

This rule is designed for °C inputs by default.Default Constants:

• Const. – Acceptable Weekly Score [%]: 60
• Const. – Hot Water Supply Temperature Deadband [°C]: 3
  • (Recommended default deadband for Fahrenheit is 5 °F)

CTL Generated:

• HWST Performance KPI

Rule Template Type

• Insight Type: Integrity KPI
• Trigger Type: Active High

Default Priority

Low

Inputs

Inputs	Units	Default Value	Tags	Description
Hot Water Supply Temperature	°C		sensor, leaving, hot, water, temp	Hot water supply temperature from boiler
Hot Water Supply Temperature Setpoint	°C		sp, leaving, hot, water, temp	Hot water supply temperature set point
Boiler Status			cmd|status	Building occupancy
Const. – Hot Water Supply Temperature Deadband	°C	3		The acceptable temperature change of the unit from setpoint
Const. – Acceptable Weekly Score	%	60		The lowest acceptable weekly KPI score

Output Calculated Trend Logs

Output CTL	Units	Description
HWST Performance KPI	%	Score representing the amount of time the hot water supply temperature is within deadband, as a percentage