HIZLI VE ÖNGÖRÜLÜ ISI BORUSU TASARIM VE ANALİZ ARACI: H-PAT

Öz

Isı borularının termal performansının değerlendirilmesi için, literatürde basit kılcal limit analizlerinden kapsamlı 3D modellere kadar geniş bir modelleme yelpazesi mevcuttur. Basit modeller, ısı transferi ve çalışma sıcaklıklarının daha düşük doğrulukla tahmin ederken, kapsamlı modeller hesaplama açısından yük getirmektedir. Bu çalışmada, geleneksel ısı borularının hızlı fakat yeterince doğru bir şekilde modellenmesi için evrensel bir hesaplama yöntemi geliştirilmiş ve bu yönteme dayalı olarak Isı Borusu Analizi Araç Aracı, kısaca H-PAT olarak adlandırılan bir analiz aracı sunulmuştur. Bir tanı aracı olarak H-PAT, kuruma başlangıcına kadar değişen ısı girdileri altında bir ısı borusundan sıvı akışını ve ısı transferini tahmin edebilir. Faz değişim hızlarının ilk tahmini sırasında, hesaplama alanı için sonlu eleman/hacim tabanlı yöntemler kullanmak yerine, ısı borusu boyunca sıvının kütle akış hızı için uygun bir model belirlenerek belirli ince film faz değişim modellerinin çözümlerinden kaçınılır. Modüler bir yapının yardımıyla, H-PAT, ortalama sıvı hızı ve buna karşılık gelen basınç düşüşü için bir formülasyon sunulabildiği sürece farklı fitil yapılarına sahip ısı borularını simüle edebilir. H-PAT ayrıca değişken kesitli ısı borularını, yerçekiminin pozitif/negatif yönde etki ettiği koşullarını da analiz etme yeteneğine sahiptir ve ısı girdisine duyarlı buhar basıncı ile evaporatör, kondenser ve adyabatik bölgelerde sıcaklığa bağlı termo-fiziksel özellikleri kullanır. Buna ek olarak, H-PAT hesaplamayı çok hızlı gerçekleştirir ve bu da onu termal yönetim alanındaki araştırmacılar ve tasarım mühendisleri için mükemmel bir tasarım aracı haline getirir.

Anahtar Kelimeler

• Isı borusu modellemesi
• düz oluklu ısı borusu
• faz değişimi modellenmesi
• H-PAT.

FAST AND PREDICTIVE HEAT PIPE DESIGN AND ANALYSIS TOOLBOX: H-PAT

Öz

For the assessment of the thermal performance of heat pipes, a wide range of modeling is available in the literature, ranging from simple capillary limit analyses to comprehensive 3D models. While simplistic models may result in less accurate predictions of heat transfer and operating temperatures, comprehensive models may be computationally expensive. In this study, a universal computational framework is developed for a fast but sufficiently accurate modeling of traditional heat pipes, and an analysis tool based on this framework, named Heat Pipe Analysis Toolbox, in short H-PAT is presented. As a diagnostic tool, H-PAT can predict the fluid flow and heat transfer from a heat pipe under varying heat inputs up to the onset of dryout. During the initial estimation of phase change rates, the solutions of particular thin film phase change models are avoided by specifying an appropriate pattern for the mass flow rate of the liquid along the heat pipe rather than using finite element/volume based methods for the computational domain. With the help of a modular structure, H-PAT can simulate heat pipes with different wick structures as long as an expression for the average liquid velocity and corresponding pressure drop can be introduced. H-PAT is also capable of analyzing heat pipes with variable cross-sections, favorable/unfavorable gravity conditions and utilizes temperature dependent thermo-physical properties at evaporator, condenser and adiabatic regions together with heat input sensitive vapor pressure. In addition, H-PAT performs the computation very fast which also makes it a perfect design tool for researchers and design engineers in the field of thermal management.

Anahtar Kelimeler

• Heat pipe modeling
• flat-grooved heat pipes
• phase-change modeling
• H-PAT

Kaynakça

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