Linear Variable Differential Transformers (LVDTs) are essential components in industrial measurements, offering precise and reliable data on linear displacement. These electromechanical sensors convert linear motion into an electrical signal, making them invaluable in various industries, particularly in the measurement of valve position & casing expansion on steam turbines.
In this article, we’ll explain how LVDTs work and how they can contribute to improve performance in industrial turbine applications.
How Do LVDTs Work?
An LVDT consists of a primary coil and two secondary coils wound on a former or bobbin. A core with iron content moves linearly within these coils, the movement of which alters the voltage induced in the secondary coils. The difference in voltage between these coils is proportional to the displacement of the core. This setup allows for highly accurate and repeatable measurements, even in harsh environments.
What Are Some Common Applications Of LVDTs?
LVDTs are widely used in industries that require precise measurement of linear displacement. Common applications include using them as feedback transducers for actuator or valve position, thermal expansion of the casing on steam turbines (bearing pedestal movement), crack monitoring, roller position, various measurements for tunnels, bridges, railways, monitoring the position of moving parts in machines, measuring the thickness of materials, and gauging the depth of boreholes. Due to their robust design and ability to operate in extreme conditions, LVDTs are also used in the aerospace, automotive, and civil engineering sectors.
One of the most critical applications of LVDTs is in the power generation industry, particularly in steam turbines.
How LVDTs Measure Casing Expansion On Steam Turbines
Steam turbines are vital in power plants, converting steam energy into mechanical energy to generate electricity. However, these turbines operate under extreme temperatures and pressures, causing the turbine casing to continuously expand and contract. Monitoring this expansion is essential to ensure the turbine operates efficiently and safely, and anticipate any potential problems that could cause downtime if left unchecked.
LVDTs play a vital role in measuring casing expansion on steam turbines. By attaching an LVDT sensor to the turbine casing, any expansion or contraction can be detected with incredibly high precision. The LVDT provides continuous real-time data, allowing operators to monitor the thermal expansion and make necessary adjustments to maintain optimum operational performance.
So, why is obtaining this measurement critical? Excessive expansion of the turbine casing can lead to misalignment of the rotor and stator, resulting in reduced efficiency or even catastrophic failure. By using LVDTs, operators can promptly detect and address potential issues before they escalate, ensuring the turbine operates within safe limits.
For More Information, Contact Sensonics Today
At Sensonics, our experienced team can help you to gain greater oversight and control of the operation of your turbines, enabling you to assess their performance and anticipate emerging technical problems.
To find out more, please get in touch with us today.
