rebible
04-07-2013, 09:53 PM
I have a mobile AC unit that we use for cooling a survey instrument. It has a masterflux variable speed compressor and a Danfoss TUAE expansion valve.
I would like to automatically control the compressor speed to keep a steady output air temp.
But as I understand it the expansion valve is already controlling the coolant flow into the evaporator to keep the suction temperature constant. The bulb is mounted on the exit of the evaporator coils.
If I slow the compressor isn't the valve simply going to open up and put more coolant through the evaporator. I guess that at some point the valve is completely open and the evaporator temperature is controlled by the compressor rpms,, but that doesn't sound like a good solution.
I am looking for comments.
I would like to automatically control the compressor speed to keep a steady output air temp.
But as I understand it the expansion valve is already controlling the coolant flow into the evaporator to keep the suction temperature constant. The bulb is mounted on the exit of the evaporator coils.
If I slow the compressor isn't the valve simply going to open up and put more coolant through the evaporator. I guess that at some point the valve is completely open and the evaporator temperature is controlled by the compressor rpms,, but that doesn't sound like a good solution.
I am looking for comments.