cooldown rate

例句：

1. 1.The cooling down of the engine is crucial for safe operation.
   发动机的冷却对于安全运行至关重要。
2. 2.The manufacturer has set a target for the maximum cooldown time.
   制造商已经设定了最大冷却时间的目标。
3. 3. During the cooldown period, the temperature drops significantly.
   在冷却期间，温度显著下降。