開放迴路脈衝式熱管之無因次參數數值分析

Nondimensional Parameters’ Simulation of Open-Loop Pulsating Heat Pipe

許展榕(Chang-Jung Hsu)

指導教授 ： 林水泉 ； 王金樹

國立臺北科技大學/機電學院/製造科技研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00199

摘要

本研究以α（能量比）、β（密度空隙比）、γ（空隙填充率）、Rm（質量比）四個無因次參數來說明開放迴路脈衝式熱管之參數。可模擬出振盪與非振盪之臨界值，其中α代表內能與動能比值，β代表密度比與空隙率的乘積，γ代表空隙率與填充率的比值，Rm代表質量蒸發量與流動量的比值。
本研究利用EES（Engineering Equation Solver）發展出兩個人機介面的軟體，分別為PHP.ees，此程式將液柱的連續、動量方程式與氣柱連續、能量方程式再加上狀態方程式五個式子在EES內解聯立，以得知開放迴路脈衝式熱管內之物理量變化；及Txt.ees，這個部份利用液柱能量方程式推導出液柱溫度曲線，以求得顯熱熱傳量。EES是一個具有內建熱性質資料庫且可製作出人機介面的運算軟體，此次利用EES程式來模擬乃是由於上述優點，且製作出人機介面後，能讓對EES不甚熟悉者也可以順利操作，使得開放迴路脈衝式熱管的設計上能更簡單明瞭。
吾人將幾何固定後，β將僅僅為填充率之函數，此時可於α為4126時得出一可振盪區域與填充率改變範圍圖，如圖4.11、圖4.12、圖4.13及圖4.14，可振盪填充率範圍為0.6~0.68。
在經由模擬表4.1後，可以找出單一液柱最大散熱量為16.15（W），最大吸熱量為0.3463（W），則在此系統含有兩個等長的液柱，則此系統最大散熱量約可到32.3（W）。

關鍵字

能量比 ； 密度空隙比 ； 空隙填充率 ； 質量比 ； EES ； 人機介面

並列摘要

This research is to make a description of open-loop pulsating heat pipe’s parameter by using four nondimentional parameterα（energy ratio）,β（density empty ratio）,γ（empty filling ratio）,Rm（mass ratio）.After simulating,we can find no oscillation zone and oscillation zone.In our simulation,α is meaning of internal energy divided by kinetic energy’s ,βis meaning of empty volume ratio divided by density ratio,γis meaning of empty filling ratio divided by filling ratio,Rm is meaning of mass evaporating rate divided by flow rate.
In this research,we develop two software by EES（Engineering Equation Solver）,one is PHP.ees ,this software is using slug’s continuity and momemtum equation , plug’s continuity and energy equation and state equation,these five equation will solve by EES in order to understand open-loop pulsating heat pipe’s thermal property’s variety;another is Txt.ees,this software is using slug’s energy equation to slove a slug’s temprature distribution,then calcuting the slug’s heat transfer rate.EES is a software with bulid-in thermal property’s database and can create GUI ,it is why we use this software in this research .After creating GUI ,it will be easier to operate for people who doesn’t understand EES very much ,and it will let open-loop pulsating heat pipe’s design more easier.
When we let geometry fixed ,β becomes function of filling ratio .Then we could find out an oscillation area changed with filling ratio ,when α is 4126 .As Fig 4.11 ,Fig 4.12,Fig 4.13 and Fig 4.14 ,filling ratio changes from 0.6 to 0.68 in oscillation area.
After simulating Table 4.1 , we could find there is a maximum heat transfer rate 16.15(W) in one slug , and there are two equal slugs in this system , the maximum heat transfer rate in this system is 32.3(W).

並列關鍵字

Energy Ratio ； Density Empty Ratio ； Empty Filling Ratio ； Mass Ratio ； EES ； GUI

參考文獻

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