labels said:
These are used in a counter flow configuration normally.
Technically, when the wort reaches the end of the chiller it should be the same temperature as the starting water temperature and when the water reaches the end of the chiller it should be the same as the starting temperature as the wort. This is mad theory of course because my chiller does not come close to this.
However, my question is, if you have 100C wort going in one end and 20C water going in the other at what point would the temperature of the water and the wort be the same and what would that temperature be?
Yes.
If you were to hold the wort in the chiller and the cooling water in the chiller, they would reach an equilibrium temperature. Neither are really held in the chiller as both are flowing through it.
Perhaps if it was an exceptionally long chiller then they could reach an equilibrium temperature before they exited, also again this would be dependent upon flow rates. The longer the chiller the more potential for heat transfer to occur, thus you could flow the wort through faster. Likewise a chiller with more plates has a larger contact area for heat exchange, so you can run the wort through faster. Likewise if you prechill the cooling water, you don't need to flow it through the chiller as fast, thereby saving the amount of water you pass through the chiller (and reducing the amount of water used or that has to be stored). If you recirculate to a rain water tank then flow your hardest. However don't flow too hard because the cooling water will need to remain within the chiller long enough to actually absorb some of the heat energy.
To answer your last question: assuming the wort is actually at 100oC and has not dropped any temperature during whirlpooling, or transferred any of its heat to the vessel or pipework on its way to the plate chiller and that the cooling water is entering at 20oC: it would depended on the length of the plate chiller, the number of plates in the plate chiller, the width of the plate chiller (since depth is largely determined by the number of plates), the flow volume (aka speed) of wort flow, the flow volume (aka speed) of the cooling water, the potential flow rate of the plate chiller (which probably relates to the number and dimensions of the internal channels), the type or material of the hosing used in the plumbing (i.e. copper plumbing would lose some heat as radiant energy loss more rapidly than say silicone hosing), is the procedure happening outside in a windy place (what temperature is the wind?) or inside a shed sheltered from wind, the thermal capacity of the wort (perhaps higher viscosity wort such as those made from Rye might have a differing thermal capacity?), the ambient temperature and probably what coloured undies you are wearing.
I hope this simplifies it for you.