| 摘要 |
PROBLEM TO BE SOLVED: To detect the present or absence, or shortage of heating medium liquid without any time lag. SOLUTION: Heat medium liquid is circulated to a water jacket for cooling an engine 2 and a waste gas heat exchanger 9 with an engine exhaust as a heat source. A first temperature sensor TW1 is provided near the engine 2 as a waste heat collection position on a circulation path 12 of the heat medium liquid. A second temperature sensor TW2 is provided on a circulation path 12 at the downstream of the first temperature sensor TW1. In the case of failure where no heating medium liquid is present, a temperature difference that is larger in normal case is generated between the outputs of the first and the second temperature sensors TW1 and TW2. Then, when the detection temperature difference by the first and second temperature sensors TW1 and TW2 exceeds a scheduled value, a heat medium liquid shortage signal is outputted. |
