Exhaust heat recovery for engine heating and exhaust cooling

摘要

Various systems and method for heating an engine in a vehicle are described. In one example, intake air flowing in a first direction may be heated via a gas-to-gas heat exchange with exhaust gases. The heated intake air may then be used in a subsequent gas-to-liquid heat exchange to heat a fluid circulating through the engine. In another example, intake air flowing in a second direction may be heated via a heat exchange with exhaust gases in order to cool an exhaust catalyst.

主权项

1. A vehicle engine heating method, comprising:
heating intake air drawn from upstream of a turbocharger via a gas-to-gas heat exchanger, the gas-to-gas heat exchanger in communication with exhaust gases; then heating a fluid with the heated intake air via a gas-to-liquid heat exchanger, the fluid flowing through the engine; and adjusting a valve to reduce a flow of the fluid through the gas-to-liquid heat exchanger when a temperature of the fluid is greater than a threshold temperature.