Helisel sarılmış ısı eşanjörünün deneysel ve sayısal analizi

Bu çalışmada, helisel ısı eşanjörlerinin ısı transferi karakteristikleri sürekli şartlarda araştırılmıştır. Deneylerde soğuk suyun eşanjöre giriş sıcaklığı 20 °C, sıcak su sıcaklığı ise 50 °C olarak belirlenmiştir. Soğuk suyun debisi 2 – 3 – 4 ve 5 L/dk olarak ayarlanmıştır. Soğuk suyun eşanjörden çıkış sıcaklığı ölçülmüş ve iç taraf Nu sayısı hesaplanmıştır. Sayısal çalışma için eşajörün üç boyutlu modeli oluşturulmuştur. Hesaplamalı akışkanlar dinamiği paket programı (Fluent 18.2) kullanılarak eşanjördeki ısıl özelliklerin ve hız konturlarının belirlenmesi için sayısal analiz gerçekleştirilmiştir. İç taraf Nu sayısı ve soğuk suyun eşanjörden çıkış sıcaklığı deneysel çalışmada elde edilen verilerle karşılaştırılmıştır. Hesaplamalı akışkanlar dinamiği sonuçlarının deneysel bulgularla uyumlu olduğu tespit edilmiştir.

Anahtar Kelimeler:

Helisel ısı eşanjörü, Nu sayısı, Isı transferi, HAD

Experimental and numerical analysis of helical coiled heat exchanger

In this study, heat transfer characteristics of helical heat exchangers were investigated under steady state conditions. In the experiments, the inlet temperature of the cold water into the heat exchanger was set as 20 °C and the hot water temperature was set as 50 °C. The flow rates of cold water were set as 2 - 3 - 4 and 5 l/min. The outlet temperature of the cold water from the heat exchanger was measured and the inside Nu number was calculated. For numerical study a three dimensional model of the heat exchanger was designed. Numerical analysis was carried out to determine the thermal properties and velocity contours in the heat exchanger using a computational fluid dynamics software program package (Fluent 18.2). The inside Nu number and the outlet temperature of the water from the heat exchanger were compared with the data recorded in the experimental study. The computational fluid dynamics results were obtained to be in agreement with the experimental results.

Keywords:

Helical coiled heat exchanger, Nu number, Heat transfer, CFD,

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