Hi all,

When designing an ammonia pumped recirculation system, what pressure drop (pumped liquid pressure vs evaporator pressure) do designers use for standard force draft evaporators and why? Also, consequences of too high/low pumped liquid pressure?

I've looked on evaporator manufacturers data sheets and ASHRAE handbooks without success. I find on most existing sites I visit the pumped liquid pressure is generally around 3 bar above suction pressure but I'm unsure as to why this figure is chosen other than ensuring enough subcooling and satisfying the load.

Thanks