The AAD took a giant step forward some years ago in the reduction of energy consumption at the stations through the installation of the Building Monitoring and Control System (BMCS) at Casey, Davis and Mawson. This system allows us to control rather than just monitor energy usage as we have in the past.
An additional major advantage of the BMCS is that it allows on-site trades people to effectively operate and maintain the station facilities.
Through the use of 120 Controllers, the BMCS monitors and controls the services of 63 buildings across our three Antarctic stations.
The trades people can fully control and program the system from each of the two BMCS computers which are on station.
The system can also be monitored, programmed and controlled from the AAD at Kingston. The installation of the BMCS commenced in 1998 and was completed in early 1999.
Building heating and ventilation
Power at the stations is produced using conventional diesel generator sets. Waste heat that is generated from this process is used to heat water known as “heating hot water” (HHW). HHW is pumped around the stations to each of the buildings in insulated pipes, referred to locally as site services.
Within each building there is a secondary circuit which uses a heat exchanger to remove the required amount of heat from the primary circuit.
The original design of the system has the primary circuit pump running at constant speed
The BMCS controls the temperature within a building by adjusting the amount of HHW that is supplied to a building. Fuel fired boilers in the powerhouse provide make-up heat when insufficient heat is available from the engines.
In most buildings, the BMCS controls all aspects of the heating and ventilation systems.
By adjusting the hot water valve actuators, the BMCS maintains the temperature in the various occupied spaces. It also switches the ventilation fans off at night in order to conserve electrical energy. The ventilation of the buildings is controlled by the BMCS through the manipulation of the amount of fresh and exhausted air.
The BMCS monitors air quality (carbon dioxide, carbon monoxide, methane and hydrogen sulphide) and adjusts the amount of fresh air that is brought in.
The system also monitors:
- the room pressure and manipulates the exhaust air dampers to always ensure that the building is positively pressurised and hence the ingress of cold outside air and snow is limited.
- the status of fire panels and electrical switchboards. In the powerhouses, it monitors the number of engines online, warnings, fuel consumption, the power generated and the heat produced.
- wind speed, wind direction and relative humidity through an interface to the meteorological automatic weather stations.
Monitoring building services
Connecting each of the buildings on station is a system of pipes, known as site services. These provide hot water for heating, potable drinking water, fire sprinkler water and sewerage services.
The pipes are heat traced, which is best described as being like an electric blanket.
The heat trace is designed to turn on when the pipe gets too cold, and so prevents the pipe from freezing. The BMCS monitors the temperatures within these pipes and the status of the heat trace. If the heat trace fails or a pipe gets too cold, the BMCS generates an alarm.
Water production and storage
Water production at Mawson and Casey stations consists of a melt bell that utilises heat from the site services, supplemented by a diesel-fired boiler, to melt fresh water in frozen lakes adjacent to the stations.
At Davis, a reverse osmosis plant produces water over the summer months from a saline tarn.
The BMCS monitors the flow and pressure of the potable water system, and also water storage levels, production/consumption rates and temperatures.
In order to manage energy usage, it is first necessary to understand where it is being consumed. Accordingly, an electrical energy meter has been installed in each of our Antarctic buildings, along with flow meters and temperature sensors to measure the thermal energy supplied by the heating hot water.
Through analysis of the collected data, several inefficient systems have been found and we have come to understand how the buildings function under different ambient conditions.
This fact alone has enabled us to create different configurations of systems for both winter and summer periods, and therefore allowed us to operate more efficiently.
Due to the vital importance of most of the facilities and systems being monitored, a paging system provides maintenance and science personnel with indication of critical alarms, 24 hours a day.
The system has been developed by AAD personnel and some of the features include:
- discrimination of alarm priority and hence whether to transmit immediately or delay transmission until working hours.
- re-transmission or forwarding of paging message if an alarm remains unacknowledged for a specified time.
- mail drop facility updates all pagers every minute with the latest station weather information.
- search and rescue watch for when people move between buildings during periods of inclement weather and also outside of normal hours.