Heating Model
The Mechanical heating load of the house was introduced into the system.
Heating Model
The Mechanical heating load of the house introduced into the system. The energy balance was obtained by the formula:
DHW Calc
DHW Calc was used to create hot water demand profile with 1 minute time steps, format data profile produced and feed into models to explore supply options. Just assumed there are 4 occupants, and total mean daily draw-off volume is 130 L/day.
Assumptions
- m = 200kg (mass of boiler)
- cw = 4187 J/kg*C (Specific Heat of Water)
- cb = 390 J/kg*C (Specific Heat of Boiler)
- COP (heat pump) = 2.5
- Qht (Heat provided for Space Heating (J))
- Qwt (Energy used for Water Heating (J))
- If Tt <= 50, Qw = Qboiler
- If Tt >= 50, Qw = 0
- Assume 10% heat loss in boiler
Calculative process
- Calculate the Heat Provided to Boiler (J) = m×c×∆t
- Calculate the Heat Pump Gross Energy Input (J) = Q_ht+Q_wt+Q_boiler
- Calculate the Net Heat Pump Energy Input (J) = Q_HP×(1-10%)
- Convert (J) to (w min): Q=Q_(net HP)×2.77778×[10^(-4)]×60
- Calculate the Heat Pump Electrical Energy Demand (w min) = Q/2.5