Shipping Engine Exhaust Calculation And Its Virtual Instrumentation System Development Based On LabVIEW

Due to the relatively high thermal efficiency and operation reliability, Diesel Engines will still be the main engine in the near future. Considering the deteriorating environmental problem caused by the emissions from ships, people pay more and more attention to the pollution problems of Marine Diesel Engines. Under this situation, IMO issued the ANNEX VI of MARPOL Convention, which has been carried out since January 1,2000.Virtual Instrumentation (VI) is becoming a popular tool in measurement, test and automation as a result of rapid development of computer technology. And data acquisition is one of the principal functions of virtual instruments, and also the first step in all tests and measurement tasks. As the development tool for virtual instruments, LabVIEW is featured with strong software support to DAQ products, so it is easier and more convenient to realize data acquisition in LabVIEW. Taking DAQCardTM-6024E (made by NI Company in US) and NGA2000 MLT Analyzer (made by Rosemount Company in US) for example, the paper demonstrates the VI system design.In this paper, a calculating program is developed to calculate the NOx content of engine exhaust, which is according to the Annex VI of MARPOL convention established by International Maritime Organization (IMO) that prescribes the indirect measure method of the emission and its testing criterion. Then, a kind of virtual instrumentation as the shipping engine emission test experimental system comprised of laptop, PCMCIA-6024E data collection card, NGA2000 MLT Analyzer and other components is developed, so as to Real-Time acquire, selective store, print the waveform and publish the data collected from the emission of marine diesel engines. These signal outputs from NGA2000 MLT Analyzer are transmitted to DAQCard-6024E by conditioning circuits and CB-68LP, a connecting board with 68 pins. The accuracy and stability of the whole DAQ system has been proved satisfactory. The system software has been developed using LabVIEW, which offers the system a lot of merits, such as friendly user interface, low cost of development, short development period, and flexible functional-extension, etc.