samux12
08-03-2013, 01:00 PM
Hello fellas,
My company is manufacturing brine/water heat pumps.
To ensure proper refrigerant volume to evaporator we are using Danfoss ETS6 electronic expansion valves. Controller - Danfoss MCX061V with integrated EEV controller.
As we all know EEV ensures precise Superheat of refrigerant before getting to the compressor.
Yesterday one customer complained for us that heat pump is working very inefficiently. When we made the examination of that heat pump we noticed that ETS6 reaction time of reaching the desire Superheat value is very long. It takes almost about 30 minutes when the superheat drops from 20K to 10K, and the setpoint value - 6K didn't reach at all.
First of all I thought that heat pump is starving from low refrigerant volume, but when i turned EEV to manual control I could set 6K superheat very easily, and after that the system is working under designed condition.
Working conditions is listed below:
Return/supply water - 30C/36C
Return/supply brine - 5C/2C
Condensation temp - +48C
Evaporation temp - -6C
Superheat - 13K (after 20 minutes from starting of heat pump)
After EEV manual setting:
Return/supply water - 30C/36C
Return/supply brine - 5C/2C
Condensation temp - 39C
Evaporation temp - 0C
Superheat - 6K
Can anybody tell me, why EEV is reacting so slow?
Do all EEVs are working the same?
IF not, whose fault is for that. Maybe something wrong is for Danfoss MCX 061V controler?
My company is manufacturing brine/water heat pumps.
To ensure proper refrigerant volume to evaporator we are using Danfoss ETS6 electronic expansion valves. Controller - Danfoss MCX061V with integrated EEV controller.
As we all know EEV ensures precise Superheat of refrigerant before getting to the compressor.
Yesterday one customer complained for us that heat pump is working very inefficiently. When we made the examination of that heat pump we noticed that ETS6 reaction time of reaching the desire Superheat value is very long. It takes almost about 30 minutes when the superheat drops from 20K to 10K, and the setpoint value - 6K didn't reach at all.
First of all I thought that heat pump is starving from low refrigerant volume, but when i turned EEV to manual control I could set 6K superheat very easily, and after that the system is working under designed condition.
Working conditions is listed below:
Return/supply water - 30C/36C
Return/supply brine - 5C/2C
Condensation temp - +48C
Evaporation temp - -6C
Superheat - 13K (after 20 minutes from starting of heat pump)
After EEV manual setting:
Return/supply water - 30C/36C
Return/supply brine - 5C/2C
Condensation temp - 39C
Evaporation temp - 0C
Superheat - 6K
Can anybody tell me, why EEV is reacting so slow?
Do all EEVs are working the same?
IF not, whose fault is for that. Maybe something wrong is for Danfoss MCX 061V controler?