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EEV installation for TELECOM Italia
01/03/2006
EEV installation for TELECOM Italia
The EEV solution (Electronic Expansion Valve) integrated into the pCO series controllers supplied by CAREL was installed and analysed at a TELECOM ITALIA installation in Mestre (Venice), on a 110 kW water chiller in each of the two circuits operating on R22, with a mechanical thermostatic valve (TEV), two dual-stage compressors and stepped condenser control.
This retrofit solution involved the creation, in one of the two circuits, of two parallel expansion lines, one with a TEV and the other with an EEV, activated alternately by solenoid valves; this allowed comparative tests to be conducted between the two systems in the same environmental and load conditions. A CAREL EVD series driver was used to control, based on the readings from two probes, the superheat and valve positions with PID logic, so as to guarantee the maximum efficiency of the evaporator. The driver and electronic valve were integrated into a CAREL pCO series controller that continuously monitors the condensing pressure in the circuit, communicating with a phase control module, and measuring the electricity consumption and water-side cooling capacity. The pCO controller also manages the changeover between the two control technologies. The controllers can be connected to the PlantVisor supervisor for monitoring and setting the unit parameters from a remote position.
The unit analysed is part of a system made up of 6 chillers with similar characteristics, and which together provide the installation a maximum cooling capacity of around 900 kW.
The experience has shown considerable margins of improvement in terms of energy savings in air-conditioning systems for TELECOM applications. For an installation with a rated capacity of 900 kW the energy savings achieved were 14.2%, which for the installation in question means € 20,000 per year. At the same time, there is a reduction in the environmental impact in terms of CO2 emissions from the generation of electricity.
+402200120
This retrofit solution involved the creation, in one of the two circuits, of two parallel expansion lines, one with a TEV and the other with an EEV, activated alternately by solenoid valves; this allowed comparative tests to be conducted between the two systems in the same environmental and load conditions. A CAREL EVD series driver was used to control, based on the readings from two probes, the superheat and valve positions with PID logic, so as to guarantee the maximum efficiency of the evaporator. The driver and electronic valve were integrated into a CAREL pCO series controller that continuously monitors the condensing pressure in the circuit, communicating with a phase control module, and measuring the electricity consumption and water-side cooling capacity. The pCO controller also manages the changeover between the two control technologies. The controllers can be connected to the PlantVisor supervisor for monitoring and setting the unit parameters from a remote position.
The unit analysed is part of a system made up of 6 chillers with similar characteristics, and which together provide the installation a maximum cooling capacity of around 900 kW.
The experience has shown considerable margins of improvement in terms of energy savings in air-conditioning systems for TELECOM applications. For an installation with a rated capacity of 900 kW the energy savings achieved were 14.2%, which for the installation in question means € 20,000 per year. At the same time, there is a reduction in the environmental impact in terms of CO2 emissions from the generation of electricity.
+402200120
