| 摘要 |
A method is provided for testing the performance of a vehicle-mounted heat exchanger and determining whether debris is preventing air from efficiently passing through the heat exchanger. To test performance, after the vehicle is traveling faster than a preset minimum speed, the power to the DC fan motor that is adjacent to the heat exchanger is interrupted and the back EMF of the motor is used to determine fan motor speed. As rotation of the unpowered fan motor is due to the air flowing through the heat exchanger, the rate of fan rotation is used to indicate the relative health of the heat exchanger. If the rotation of the fan motor indicates insufficient air flow, then a notification message (e.g., visual or auditory warning indicator) is transmitted. If the test indicates sufficient air flow, normal operation of the fan motor is re-initiated and power is re-connected to the motor. |
| 主权项 |
1. A method of verifying performance of a heat exchanger, wherein the heat exchanger is mounted within a vehicle, wherein the heat exchanger is exposed to ambient air flow when the vehicle is in motion, and wherein a DC fan motor is mounted in a position adjacent to the heat exchanger, the method comprising the steps of:
monitoring a vehicle speed corresponding to said vehicle; comparing said vehicle speed to a preset vehicle speed, wherein when said vehicle speed exceeds said preset vehicle speed the method further comprises the steps of:
temporarily disconnecting a power source from said DC fan motor, wherein said step of temporarily disconnecting said power source is performed by a DC motor controller;measuring a back electromotive force (BEMF) of said DC fan motor;calculating an actual motor speed from said BEMF; andcomparing said actual motor speed to a minimum acceptable motor speed, wherein if said actual motor speed is less than said minimum acceptable motor speed said DC motor controller performs a first operation, and wherein if said actual motor speed is greater than said minimum acceptable motor speed said DC motor controller performs a second operation, wherein said first operation is comprised of the step of transmitting a diagnostic message, and wherein said second operation is comprised of the steps of re-initiating a normal operation for said DC fan motor and re-connecting said power source to said DC fan motor. |
