2015 CSCE Annual Conference Regina - Building on our Growth Opportunities

2015 CSCE Annual Conference Regina - Building on our Growth Opportunities Conference


Title
A distributed temperature sensor network to measure and infer frost penetration.


Author(s)
Dr. Robert (Bob) McLeod, Faculty of Engineering, University of Manitoba (Presenter)
Dr. Marcia Friesen, University of Manitoba
Mr. Blake Podaima, University of Manitoba
Dr. James Blatz, University of Manitoba
Abstract

Municipal water supply line freezing is a seasonal problem in cold-climate areas. In 2014, Winnipeg had over 2300 homes' municipal water supply lines freeze, generally at depths of 8ft below grade and often beneath roadways or other areas not insulated by snow cover. Upon having supply lines thawed, residents were required to run their taps into late June to prevent refreezing, as frost continued to penetrate downward well after ambient temperatures had turned moderate in the springtime. A system of distributed sensors were installed to monitor ground and water temperature.  The objective is to demonstrate a means to pre-emptively predict potential service interruptions due to supply line freeze-up.  Temperature sensors were installed at grade, at 8 feet below grade, and at the ingress to the residence at the water meter to monitor water supply line temperatures in the City of Winnipeg.   The prototype employs Arduino based LM35 temperature sensors with data transmission over wireless (XBee) as well as five commercial thermistor sensors (Lascar) with cloud data collection over Wi-Fi. Data integration includes weather data from Environment Canada, estimated frost penetration from the City of Winnipeg Water and Waste Department, as well as the sensor data collected directly. As of January 15, 2015, fitting the below grade temperature data with a second order polynomial predicts temperatures 8 feet below grade to reach approximately 4 degrees Celsius in mid-April. In January 2015, water supply temperatures of approximately 4 degrees C were consistently cooler than the surrounding ground temperatures.