Original Date: 07/21/2003
Revision Date: 01/18/2007
Best Practice : Energy Management System
Electric Boat Corporation, Quonset Point Facility realized many benefits from implementing a PC-based Energy Management System to control heating, ventilation, air conditioning units, air compressors, steam valves, boilers, and lights throughout the facility.
Electric Boat Corporation, Quonset Point Facility’s (EBQP’s) heating, ventilation, and air conditioning (HVAC) units, air compressors, steam valves, boilers, and lights were independently controlled. This required a maintenance technician to go to a specific unit to take readings of critical operating parameters to determine if the device was functioning correctly. Operating equipment independently was inefficient in terms of cost and energy.
EBQP implemented a PC-based Energy Management System (EMS) to control HVAC units and steam valves, monitor electricity and argon consumption, and regulate air compressors. Using Carrier Comfort Works’ software and sensors, the EMS performs two major functions by constantly monitoring critical facility operations via sensors, and controlling standard on/off processes so output is proportional to demand. This PC-based system also monitors alarm points, and sends visual warnings to designated computer terminals and pagers when triggered. Monitored alarm points include air compressor inter-cooler temperatures, oil temperatures, air pressure, HVAC air handling fans, office space temperatures, relative humidity, carbon monoxide content, and temperature parameters in critical areas.
Currently the EMS controls the office space temperature to within a one-degree variance by using an algorithm to read the outside air temperature, current space temperature, and desired temperature. Based on these inputs, the system adjusts the heating valves, cooling valves, and outside air dampers to maintain the set point temperature. The EMS constantly monitors the compressed air system to maintain the desired air pressure. As pressure drops due to higher demands, the program ramps up the lead compressor to a higher output. If this is insufficient to meet demand, the EMS brings the secondary compressors on-line. Once the desired pressure is achieved, the system will begin to ramp down the compressors to avoid over-pressurization. Based on the outside air temperature, the EMS automatically adjusts the steam heat valves and the chiller plant to heat and cool the offices.
The EMS allows EBQP to operate more efficiently, and has saved thousands of dollars in annual energy costs. Maintenance personnel can now monitor all critical operations through a computer without needing to examine a specific operating unit.
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