蛇管式熱交換器在飲水機溫水系統之應用

本論文研究蛇管熱交換器在飲水機溫水系統之熱交換情形，探討改變蛇管熱交換器之蛇管長度效率最佳化，並使用EES軟體(Engineering Equation Solver)模擬，以實驗驗證。吾人最佳化設計範圍之蛇管長度在4(m)至10(m)之間，當蛇管由4(m)增長到10(m)時，熱水質量流率由4.101E-02(kg/s)降至3.414E-02(kg/s)，冷水質量流率由5.245E-02(kg/s)降至3.317E-02(kg/s)；蛇管面積由1.065(m^2)增加至2.661(m^2)。蛇管長度5.7m的熱交換器有最大的冷水吸熱率99.8%，蛇管長度4(m)至5.7(m)，蛇管長度與吸熱效率正相關，5.7(m)至10(m)，蛇管長度與吸熱效率呈現負相關。吾人在蛇管式交換器模型加入空氣散熱的因子，計算出空氣對流係數由25(W⁄(m^2∙) K)增至500(W⁄(m^2∙) K)，空氣對流散失熱傳量與冷水側吸收熱傳量的比例是1/244至1/293。

關鍵字

飲水機；蛇管熱交換器； EES

並列摘要

This thesis snake-pipe heat exchanger drinking water system in the case of heat exchange to explore the changing snake snake tube heat exchanger tube length optimize efficiency, and using the software EES (Engineering Equation Solver) simulations, and experimental verification. I set the range of optimum design length of the snake tube 4 (m) to 10 (m), and when the snake-pipe from 4 (m) increased to 10 (m), then the hot water mass flow rate from 4.101E-02 (kg / s) down to 3.414E-02 (kg / s),cold water mass flow rate from 5.245E-02 (kg / s) down to 3.317E-02 (kg / s); snake-pipe areas from 1.065(m^2) increased to 2.661(m^2). Snake-pipe Length 5.7m heat exchanger has the largest water heat absorption rate of 99.8%, the snake-pipe length 4 (m) to 5.7 (m), the flexible tube length absorbing efficiency of positive correlation, 5.7 (m) to 10 (m), the flexible tube length endothermic efficiency negatively correlated. this article joins the air factor in heat exchanger mode, air convection coefficient input from 25 (W / (m^2)∙ K) to 500 (W / (m^2) ∙ K),then air convection heat loss the amount of the cold water side absorbent pass heat transfer ratio of the amount of 1/244 to 1/293.