I have a need to directly model the heat exchange between cold water droplets (and their evaporation) and hot process air. There arent any off-the-shelf blocks for my needs in the standard library, so it looks like I'm rolling my own.
I have plans to progress the block model in various stages since the interaction between water droplets and air isnt instantaneous, but Im not confident enough to implement some of the finite difference/volume methods I've seen in Modelica By Example just yet.
For the moment I'm just trying to get the basic interaction down, balancing enthalpy between air and water, using some of the blocks in the Thermopower and ThermoSysPro libraries as a guide - namely the barometric condenser and cooling tower blocks.
I think I've got the mass conservation down (TBF its pretty hard to mess up that all the incoming mass from inlet ports needs to equal the outgoing mass to outlet ports) but Im having a harder time with the heat exchange process.
Am I ok with:
Calculating a specific heat flux rate (Qdot/kg) from the air to the water;
Subtracting this specific heat flux rate from the air medium specific enthalpy, and adding it to the water specific enthalpy;
Setting a conservation equation that the sum of enthalpy in = sum enthalpy out.
I've currently got the water as two phase medium and the air and water "circuits" (if this was a normal tube heat exchanger) have their own separate inlets and outlets. At some later stage I'd like to have the model reflect reality and have the steam/water vapour and air mixture leave the block via a single connector, but my knowledge of the medium functions isnt good enough for that yet.
If anyone can lend some insight to this problem I'd deeply appreciate it.