Reduced scaling problems on water cooled systems
when a small amount of high pressure liquid from the pump outlet is injected into the
discharge line, reducing the vapour temperature. Lower condensing temperature to condensing media temperature
differential due to increased heat transfer when more of the available condenser surface
is used for condensing rather than de-superheating, due to liquid injection into the
discharge line.
The LPA pump is used to pressurise the liquid line with no
temperature rise, which subcooles the liquid, ensuring vapour-free liquid delivery to the
expansion valve.
Thermostatic expansion valves will maintain capacity and meter properly with as
little as 25 psi pressure drop across the valve if vapour-free liquid is present at the
valve inlet, provided that the liquid temperature is also low. The benefits are: Proper operation of a refrigeration or air conditioning system
when minimum head pressure controls are set to reduce head pressures, thereby saving
energy and increasing capacity at mild to cold outdoor temperatures. The LPA pump
eliminates the usual problems of capacity loss and poor oil return due to operating with
low head pressures. Improved performance and efficiency of a system that has flash
vapour in the liquid line. This is especially apparent if flash vapour is a serious
problem, as in systems with excessive liquid line pressure drop, elevation gain in the
liquid line, or if the air surrounding the line is warmer than the outdoor temperature.