Thermal Protection of Rear Mounted Engine and Its Components Using a Ventilation Fan with Unique Monitoring and Fault Diagnosis Technique 2017-01-0620

The engine compartment of passenger car application contains various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the body temperature of individual component. The rise in body temperature of critical components can endanger the durability or functionality of the specific component or a system in which it operates.

The aim of this paper is to strategize thermal protection of the rear mounted engine and its components of a vehicle having radiator and cooling fan mounted in front. An additional ventilation fan with speed sensor is fitted alongside rear mounted engine and a unique monitoring technique framed in the EMS ECU to protect critical components like HT cables, alternators, ECUs, wiring harness etc. from thermal damage. The EMS continuously monitors the engine speed, vehicle speed and the PWM signal of ventilation fan to ensure the intended operation of the ventilation fan. With the implementation of additional ventilation fan it is observed that maximum engine compartment temperature does not exceed safe operating temperature limit when the vehicle is driven in all road load condition (including highway, city & gradient drive conditions) and in all vehicle operating conditions. Excessive operation at higher compartment temperature unnecessarily causes individual component durability & performance to deteriorate at considerably faster rate. Thus, method of the present disclosure ensures that every component in engine compartment is operating in safe operating limits. In-case any failure occurs in the ventilation fan, newly developed EMS diagnosis strategy identify fault and indicates the problem to the driver through telltale. EMS also restricts the vehicle speed to safely maneuver vehicle to the nearest service center for repair.