Our customer supplies hot water from a heat exchanger to other users and charges them for kilowatt hours (kW.h) used. The customer supplied calculation to compile the macro was:
The difference between water temperature out and water temperature returned x a factor x flow in liters per second.
For flow rate in liters/min
-> kW - Flowrate (1/m) / 60 x dT (C) x 4.190
-> kW - Flowrate (1/m) x dT (C) x 0.06983333
This application uses a Tiger 320 Series controller with RTD Frequency RTD input module and boiler energy calculation macro Version 1.3.