熱焓公式 ＆ 解說 ２０點 ＊

Question

問題：

Ｑ　＝　Ｕ　Ａ　△Ｔ　

Ｕ　跟　Ａ　的代表意思　？　

謝謝各位的解釋　～～　感激不盡

Answer 1

Ｑ＝Ｕ*Ａ*△Ｔ
傳送的總熱能Ｑ= 建材的熱傳透率U*建材的面積Ａ*溫度差△Ｔ

Ｕ代表的意思：建材的Ｕ值就是建材的熱傳透率，U=W/(m2.K)。熱傳透率與材料厚度有關。

Ａ代表的意思：Ａ是建材的面積，熱能由此面積以法線方向傳送過去。

建材的熱導係數 k (k values) (k是小寫)(或稱導熱係數)(Thermal conductivity)，k value =W/(m*K)，是材料的內涵性質，與材料厚度無關。(K，大寫的K代表溫度)

U = k values/材料厚度。

Q代表的意思：Q代表傳送過去的總熱能。

△Ｔ代表溫度差。

建材的熱導係數k =熱流速率 * 傳送距離/(面積Ａ*溫度差△Ｔ)
上式中， 熱流速率 =傳送的總熱能Ｑ/傳送耗用時間

In physics, therm al conductivity, k, is the intensive property of a material that indicates its ability to conduct heat.

It is defined as the quantity of heat, Q, transmitted in time t through a thickness L, in a direction normal to a surface of area A, due to a temperature difference ΔT, under steady state conditions and when the heat transfer is dependent only on the temperature gradient.

thermal conductivity = heat flow rate × distance / (area × temperature difference)