Position sensors for steam turbines
31/01/2020
NewTek has customised its linear position and linear variable differential transformer (LVDT) sensors and linear variable reluctance transducer (LVRT) inductive half-bridge sensors with mounting features, such as blocks and flanges, to fit into the existing footprint of steam turbines in order to eliminate the need for turbine operators to update or replace costly legacy equipment, including mounting equipment, brackets and mechanical indicators. LVDTs and three-wire LVRTs are installed on the steam turbine to track vibration for health monitoring and maintenance prediction and provide feedback on the open/close status of steam inlets and governor valves.As the LVDTs and LVRTs are often exposed to high vibrations, NewTek welds the stainless steel blocks and flanges to the sensors. In addition, some linear position sensors are customised with threaded connectors for long-term performance in the high-vibration environments of the turbine. Other mounting blocks or methods might become loose over time and compromise measurement quality.
AC-operated LVDTs and LVRTs are the only technologies that can survive steam exposure with high temperatures. For example, NewTek’s high-temperature HATR-750 Series of products withstand the extreme temperatures of turbines up to 204°C (400°F) with excellent linearity, high sensitivity and infinite resolution. The linear position sensors are also very resilient to the harsh vibration typically associated with turbine operation. NewTek signal conditioning provides the digital output from the AC-operated sensors in a variety of forms to meet various protocols, including Modbus, CAN Bus, RS-485 and more.
