Because of the growth Ry has seen in recent years, the number of houses requiring heat has increased significantly. As this affects the differential pressure in the network, Operations Manager Flemming Skjødt needed precise data on what pressure the utility actually delivers to its customers.
In addition, the supply area covers considerable variations in topography, the age of the pipes, energy profiles of houses and differences in end-user behaviour – all factors that are difficult for the Operations Manager to predict in his calculations to design and get the most out of his network.
Using – for a start – two Kamstrup pressure sensors, he is, therefore, working his way through the supply area one zone at a time.
Ry Heat Utility has always had differential pressure measurement in its network but until now, it has used expensive fixed pressure transmitters connected to the SCADA system and placed where it assumed the differential pressure was representative. Verification performed in other places in the network was done using a manual manometer and that makes the measurement difficult to interpret.
”The measurement is only as reliable as the moment you choose and as accurate as the manometer allows. You don’t get a history – only a very brief measurement showing a precise snapshot”, Flemming Skjødt explains.
While a few of the zones in the supply area have not changed significantly, some of the pipes date back to the late 1960s and were designed based on very different criteria. ”We have a number of pipes in the centre of town where some old concrete ducts need to be replaced, but they are from a time when we used a higher set of temperatures so they have to be recalibrated. I will be using the pressure sensors for that,” says Flemming Skjødt.
The increased precision can reduce the overmeasure often used when sizing pipes. ”The overmeasure can mean the difference between going up a size or maybe even down, so there are potential savings there.”
”If I size my distribution network based on erroneous data or theory, I risk putting 100 meters of the wrong sized pipe into the ground. In the technical world we are in, believing isn’t enough – you need to know,” says Flemming Skjødt.
According to Flemming Skjødt, the utility’s ultimate goal will always be to deliver the right product at the right price at the right time so the consumers have a positive experience. This goes for everything from the actual supply of district heating to customer service and guidance as well as minimising costs in order to lower the price of heat. ”To reach our goal, we need to know what is actually going on in our network. We get that knowledge from the pressure sensors.”
So far, Ry Heat Utility has read its heat meters twice a year using a handheld terminal, but with network reading and more frequent meter data, the utility gets even more insight into the distribution network. This will enable it to further lower the return temperature and to prioritise its renovation efforts based on the actual state of the equipment in the network.
Approx. 1,200 meters have been replaced and are read using the remote reading system, READy. The rest are read using a handheld terminal and PcBaseKamstrup pressure sensors