Yapay bir göldeki termal değişikliklerin bir boyutlu sayısal model ile simülasyonu

Yıl 2019, Cilt: 25 Sayı: 6, 655 - 664, 25.11.2019

Talia Ekin Tokyay Sinha Mehmet Yücel Yetgin

Öz

Bu
çalışma yüksek sıcaklıktaki suyun göl ve rezervuar gibi akıntısız su
kütlelerine verilmesini incelemektedir. Sayısal çalışmada PROBE isimli bir
boyutlu (1B) sonlu hacim yazılımı kullanılmıştır. Yazılım, yüksek sıcaklıktaki
suyun ve rüzgârın göl içindeki karışma süreçlerine etkisine, Koriolis etkisine
ve güneş ışınımı etkisine açıklamalar getirmektedir. Bu koşullar termik
santrallerdeki (kömür, doğalgaz, nükleer vb.) soğutma işlemleriyle alakalıdır.
Mevsimsel doğal tabakalaşma ve termoklin oluşumu sayısal yöntemlerle ışık
geçirim katsayısı, güneş ışınımı ve rüzgâr hızı kalibre edilerek gerçek bir göl
için elde edilmiştir. Yapay bir göle su girişinde ve gölden su çıkışında oluşan
termal tabakalaşma birçok durum için çalışılmıştır. Çalışma, yapay gölde, su
giriş ve çıkışının kısa dalga ışınımı ve rüzgâr etkisi ile beraber düşey termal
profile yaptığı etkiyi bir günlük (24 sa.’lik) süre için incelemektedir. 24 sa.’lik
sonuçlar ortalama bir işlemci ve bilgisayar kullanılarak dakikalar içinde elde
edilmiştir. Bu daha uzun vadedeki sonuçların kısa sürede elde edilebileceğini
göstermiş ve bu tür kodların termal mühendislik uygulamalarında ne kadar
kullanışlı olduğunu ortaya koymuştur.

Anahtar Kelimeler

PROBE, Termoklin, Termik santral soğutma sistemleri, Işık geçirim katsayısı, Güneş ışınımı

Thermal changes in an artificial lake simulated using a one-dimensional numerical model

Öz

This study
focuses on release of high temperature water to still water bodies such as
lakes and reservoirs. The numerical study is conducted using one dimensional
(1D) finite volume code, PROBE. The code accounts for effect of high
temperature water release, effect of wind over the lake in mixture processes,
Coriolis’ effect and solar radiation. These conditions are relevant in cooling
operations of thermal (coal, natural gas, nuclear etc.) power plants. Natural
stratification and thermocline formation in a real lake is achieved by
calibration of light extinction coefficient, solar radiation and wind velocity.
The inflow and outflow of water to and from an artificial lake is studied under
several scenarios when a thermal stratification exists. Study investigates the
effect of inflow and outflow of water to an artificial lake under the effect of
short wave radiation and wind for a period of one day (24 hours). Results for 24-hour simulations were obtained within minutes using
an average processor and computer. This 
shows how such 1D models are 
viable tools in thermal engineering applications when long term results
are required to be assessed in short time.

Anahtar Kelimeler

PROBE, Thermocline, Thermal power Plant cooling systems, Light extinction coefficient, Solar radiation

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