Real ship diesel engine NOx emission online monitoring system

The invention discloses a real ship diesel engine NOx emission online monitoring system. The system is characterized by comprising a data collecting terminal, a direct-plug intelligent NOx sensor, a communication unit module, a power source system and a human-computer interface touch screen, a GPRS/CDMA (general packet radio service/code division multiple access) communication module is integrated at the data collecting terminal, and the direct-plug intelligent NOx sensor, the communication unit module, the power source system and the human-computer interface touch screen are connected with the data collecting terminal respectively. Digital signals like diesel engine NOx concentration detected are output through a CAN-BUS. The intelligent NOx sensor is a direct-plug module and is directly mounted at a diesel engine waste gas pipe to measure parameters like NOx/O2, a sampling pipeline and a sampling pump are not needed, NOx emission of ship diesel engines can be monitored continuously in real time, emission values can be recorded continuously, and functions of online automatic monitoring, real-time recording, alarming and remote monitoring of real ships are realized.