barrel heater

例句：

1. 1. The barrel heater keeps the room warm during winter.
   桶式加热器在冬天保持房间温暖。
2. 2. He used a barrel heater to heat up his cabin.
   他用一个桶式加热器来加热他的小屋。
3. 3. The barrel heater was an old-fashioned way to keep warm in cold weather.
   桶式加热器是寒冷天气中保持温暖的老式方法。