January 12, 2009 - The pressure transmitter ED752 for hydrostatic pressure measurement, in combination with the DX display, is suitable for pressure measurement in the cooling water circuit of nuclear power plants. Clogging of the filter in the coolant inlet can be detected in time in order to adjust the filter rotation speed. To avoid pollution in the cooling water circuit of nuclear power plants, the cooling water drained from rivers or the sea is cleaned through a big rotating filter. The rotation speed can be adjusted according to the filter’s degree of pollution which is detected via differential pressure measurement. For that purpose, the upstream and downstream pressures are measured by two ED752.
This submersible transmitter offers a very high accuracy over a wide temperature range, an excellent repeatability and long-term stability. For applications in nuclear power plants, the ED752’s pressure range reaches from 0 to 16 mH2O. The device is available in Hastelloy C which is resistant against most aggressive liquids like seawater. The DX Display receives the signals from both ED752, calculates the differential pressure and then converts it in 4 to 20 mA analogue output. Afterwards, the DX Display activates four switching outputs according to the varying differential pressures caused by the filter pollution.
Whereas at the first two degrees of pollution, the rotation gets accelerated more, the power of the reactor is reduced at the third degree. At the fourth degree of pollution, the reactor is stopped. The pressure control with the ED752 and the DX Display has been proved in a long-term test with different pressure cycles, shocks and vibrations as well as electromagnetic radio frequency interferences (EMI/RFI). The system is installed in reactor facilities being retrofitted and in the new generation of nuclear power plants EPR (European Pressurized Water Reactor).
