EGR (Exhaust Gas Recirculation) gas temperature and EGR cooler cooling efficiency detection method

The invention relates to the technical field of engine performance detection, and discloses an EGR (Exhaust Gas Recirculation) gas temperature detection method. The method comprises steps: an EGR gas temperature detection platform is built on an engine rack, universal characteristic data of the EGR gas temperature are measured, a universal characteristic curve is drawn, corresponding engine rotation speeds and hourly fuel consumption amounts at the highest EGR gas temperature point and the lowest EGR gas temperature point are acquired respectively, the overall vehicle is then operated on a rotating hub, corresponding engine working conditions at the highest EGR gas temperature point and the lowest EGR gas temperature point are restored respectively, and an EGR gas temperature in a corresponding working condition is detected on the rotating hub. The invention also provides an EGR cooler cooling efficiency detection method. The above method is used for measuring exhaust gas temperatures at the inlet and the outlet of the EGR cooler and coolant temperatures at the inlet and the outlet in any working condition on the rotating hub, and then according to an efficiency formula for a heat exchanger, the working efficiency of the EGR cooler is calculated accurately.