Flow meter for DHS
Flow rate is a parameter paramount to efficient control of district heating systems (DHS). One of crucial parameters being subject to optimization is water temperature, which is the main factor behind system energy loss, thus overall efficiency and operating costs. Lowering water’s forward temperature could potentially reduce both of these factors, yet it can pose a serious challenge on the outskirts of DHS. Therefore, distributed flow sensors are necessary to tackle the issue and enable optimization. There is a wide array of available flow meters, yet most of these solutions are often expensive or require a large power supply. Especially the latter can pose a serious challenge in areas where grid connection may not be available. That highlights the need for development of low power or self-powered sensors. This study aims to develop a flow meter which is reliable, economically feasible and suitable for setup during DHS operation. One of the possibilities of avoiding water supply intermissions is introducing the sensor through the control valves located in the majority of heating systems piping. For that purpose, an extensive review of existing pressure based and other flow meters with potential of installation through a control valve was conducted. It was followed by designing process of a sensor based on the chosen technology. CFD Ansys Fluent software was used to obtain a simulation of the prototype. Finally, the device was tested and validated in the laboratory. The results show that the prototype flow meter is suitable for DHS control. It is expected to contribute to a successful development of low temperature District Heating System, which will result in reducing the heat losses, CO2 emissions and costs for consumers.