| 摘要 |
PROBLEM TO BE SOLVED: To heat fuel at the beginning of an engine, and to efficiently cool lubrication oil reaching a high temperature by the fuel in steady operation of the engine. SOLUTION: This heat exchanger comprises a lubrication oil heat transfer pipe 12 for flowing lubrication oil O, a fuel heat transfer pipe 13 for flowing fuel F, and a flow passage change-over solenoid valve 18 for switching flow passages of the lubrication oil heat transfer pipe 12 and the fuel heat transfer pipe 13. The flow passage change-over solenoid valve 18 switches a flow type between an opposite flow type wherein the oil O in the lubrication oil heat transfer pipe 12 and the fuel F in the fuel heat transfer pipe 13 flow oppositely to each other, and a parallel flow type wherein the oil O and the fuel F flow to an equal direction in the respective flow passages.
|
