Improved Security with Automatic Leak Surveillance
Recently one family’s house in the village Feldborg was saved from destruction because of the district heating's leak surveillance
At the CHP Feldborg-Haderup in central Jutland, the operating manager Svend Jensen is pleased with the strong position of his utility and its services in the mind of the heat customers. The utility is not only supplying the 500 residences with heat, but is in addition offering leak surveillance.
Some three years ago the utility invested in new heat meters and a radio mesh network for automatic meter reading for the sake of getting monthly readings of the consumption.
But the automatic reading has provided extra opportunities for information gathering, and especially the leak surveillance has proven to be a manifest service that strengthens the role of the utility in local society.
In 2009 a customer experienced a genuine bursting of the heating installation. One late evening Svend Jensen called the residents to inform them that they had a problem. Shortly after, he appeared at the residence and opened up into the basement from where steaming hot water was pouring out. Quickly the supply was cut off, and the day after the plumber exchanged the corroded pipes. A disaster had been averted.
The reason for the operator’s quick arrival at the residence – even before the residents themselves found out there was something wrong – lies in the automatic meter readout and in his own sense of responsibility.
The meters are linked together in a radio network. Each meter contains a radio module transmitting consumption data to a centrally placed concentrator. From the concentrator the data are being transmitted via the GSM net to the server located at Kamstrup.
Kamstrup runs a permanent operation surveillance which for Svend Jensen is ideal as he is the sole member of staff at the utility: “I have nothing to do with the actual operation of the radio network. I just receive the information. Kamstrup notifies me if there needs to be exchanged a module somewhere or mounted an extra antenna.”
Among the collected data figures the actual as well as the accumulated consumption that can be accessed directly by the operating manager from a computer on the utility.
The principle of the leak surveillance is that the meters register the actual flow by comparing forward flow with return flow. A normal flow amounts to 50-70 litres/hour. If the flow exceeds 300 litres/hour the system will automatically generate a leak alarm.
The first person to receive the leak alarm via SMS is the operating manager who can then pay a visit to the installation. The SMS contains the address. In the recent case the actual flow showed no less than 1,200 litres/hour. But a quick response ensured a shut down of the water supply after just 20 minutes from the time of the alarm. Svend Jensen received the alarm at 9.45 p.m. which is actually a good deal past normal working hours. But as he points out: “It is important to respond with equal urgency every time; even in the middle of the night or on Sundays. But it feels good to be able to offer that kind of service too. It gives the utility a stronger position in the community.”
In this way Svend Jensen has detected three serious leakages in the past two years. Small leakages used not to be detected at all, but the system is so sensitive that they are being picked up too. In that case the operating manager receives the alarm by e-mail. He can then contact the customer by phone and inform them of the problem.
Often the alarm is caused by plumbing work where the heating system is being emptied. In one case a plumber had disconnected the meter from the return flow pipe which resulted in about 50 leak alarms within two hours. “But I would rather turn out once too many times, than once too few,” says Svend Jensen.
