Why doesn't the thermos keep warm? As long as the answer is that the vacuum layer of the thermos is not vacuumed, it won't keep warm. Can an uninsulated thermos be repaired? There is only one answer: it cannot be repaired. Many friends are not very satisfied with this answer. In fact, as long as you understand the structure of the vacuum flask and the principle of the vacuum flask, it is very easy to understand. Next, let's see why the vacuum flask can keep warm.
Thermal insulation principle: To understand its principle, we must first know that there are three ways of heat transmission: radiation, convection and transmission. Insulation is to block these three heat transmission methods. The silver in the thermos cup can reflect the radiation of hot water, and the vacuum of the cup and the cup body can block the heat transfer, so the thermos cup can have a good insulation effect. Hot water can keep warm, cold water can keep cold.
