jmaguire1 / waterheaterpythonmodel Goto Github PK

For mixed flows, iterate and use the current water heater temperature rather than last timestep's temperature. This leads to some issues with a larger draw volume in python than E+

Current model is only 1 node. We'll eventually want to allow n nodes (probably 12 in most cases). Things we'll have to update:

• Different UA values for the top/bottom and middle nodes
• 2 elements, located dynamically based on number of nodes, with master/slave control
• Change tank temperature code to solve for all n node temperatures
• Calculate mixing between nodes (might require iteration)

• Calculate a mains water temperature based on location (need to understand if what site data is available from the bus)
• Simplifications for ambient air temperature

Add a model of a HPWH. This might require multinode stratified tanks . We'll also have to deal with HP performance (possibly with a performance map based on tank temp and WB temp) and control logic priority for the HP/elements.

Get a better match on water heater consumed and delivered energy consumption to EnergyPlus (currently 10% difference). Changing the draw profile calculation to use the current timestep for delivered energy should help this a bit.

Now that EF has been replaced by UEF, we'll want to change the way we change UA to work with the new test procedure. I'll be working on this for a separate project so I'll just have to add the new methodolgy into our code once I have all the equations worked out.

We'll eventually want this to run for a fleet of water heaters, so we'll need to have an automated way to run a whole bunch of water heater simulation. These are the sorts of things we'll want to vary for each run:

• Setpoint temperature
• Water draw profile
• Ambient air temperature
• Mains water temperature
• Tank volume
• Tank EF
• Service calls
• Max allowed service calls (per hour/day/year)

We'll want vary these based on:
Location (mains temperature, ambient temperature & RH)
Probability distribution (tank volume?, setpoint temperature, max allowed service calls?)

Chuck will work on a script to run an aggregate fleet of water heaters and service calls, Jeff will work on ambient conditions, tank volume, EF, setpoint temperature, and draw profile.