Chinese engineers have developed an engine monitoring system based on HBM’s GEN2i data acquisition equipment to ensure standby diesels meet enhanced nuclear safety regulations.
Safety has always been a prime concern in the nuclear industry and the importance of ensuring that back-up emergency diesels are constantly able to operate requires that their performance is constantly monitored.
Japanese regulations, for example, require that the power supply for the diesel generator supplying the power to the high-pressure core spray system in boiling water reactors (BWRs) – one of the most popular of modern designs – is constantly available. The latest US designed Advanced Boiling Water Reactor includes three emergency diesels in the design specifications.
By using HBM’s GEN2i, Chinese engineers are able to monitor and record all engine signals to quickly determine any possible malfunctions so that they can be rectified immediately.
HBM’s GEN2i provides 68 channels – 48 digital and 20 analog – for monitoring signals with the system set to continuously record at 1,000 samples/min; or just over 16 samples/sec. Any channel on the diesel engine can be monitored and the system features operator defined trigger functions such as when a signal exceeds a defined value and either enters or leaves a defined range. Examples of trigger methods include rising or falling edge triggers, dual-level triggers and window triggers.
When triggered the GEN2i switches to a faster sampling rate of 1,000 samples/sec enabling signals to be immediately captured before and after any potential failure. The actual time that the GEN2i operates at this higher data capture rate can be user-defined. This enables any alert to be immediately and quickly identified so that swift remedial action can take place.
The GEN2i features high-speed, multi-channel, continuous recording that integrates Windows 7 operating system. It comes equipped with 17-inch touch screen for easy on-site real-time observation of the signal waveform and can easily be connected to a PC or laptop for subsequent data analysis.
The system devised by the Chinese engineers utilizes a 32 channel differential analog card to collect 0-10V voltage signal and 4-20mA current signal with 16-bit A/D resolution per channel at an accuracy of 0.1% and a maximum sampling rate of up to 20kS/s.
There is also a 64 channel digital card with a maximum sampling rate of 1MS/s. The card features 512MB of memory, has 64-channel TTL digital inputs and three channels for revolution and frequency measurement.
Once high-speed recording is completed, the GEN2i resumes its standard recording state. By utilizing the GEN2i in this way the engine can be monitored over a long time at low recording rates with – once failure occurs – the system automatically recording at a higher rate to ensure that the maximum data relating to any fault is correctly captured for analysis.
GEN2i Data Recorder