Method and device for regulating the cooling of oil in a turbomachine

A method for regulating oil cooling within an oil cooling device of a turbomachine including a first heat exchanger mounted in series with a second heat exchanger, the first heat exchanger being an oil/air exchanger and the second heat exchanger being an oil/fuel exchanger, each heat exchanger having an oil inlet and an oil outlet, a bypass directly connecting the oil inlet of the first heat exchanger to the oil outlet of the first heat exchanger, and a flow regulator to regulate a flow rate of oil flowing through the bypass, the flow regulator including a thermal valve and a pressure valve arranged in parallel, the method comprising:

• opening the thermal valve when temperature of the oil is less than or equal to a predetermined temperature comprised between 70° C. and 90° C. so that the oil circulates through the bypass;
• opening the pressure valve when a ratio between a nominal head loss of the first heat exchanger and an effective head loss between the oil inlet and the oil outlet of the first heat exchanger is less than or equal to a predetermined ratio comprised between 0.7 and 0.9 so that the oil circulates through the bypass;
• and
• closing the thermal valve when the temperature of the oil is greater than the predetermined temperature and closing the pressure valve when the ratio is greater than the predetermined ratio so that the oil circulates through the first heat exchanger.