Yatay deşarj edilen soğuk-yoğun atıksuların bazı deşarj parametrelerinin belirlenmesi

Termal kirlilik, okyanus, göl veya nehir gibi sucul alanlarda ortam sıcaklığının insan faaliyetleri sonucunda artması veya azalması olarak tanımlanır. Termal kirliliğe, enerji santralleri, sıvılaştırılmış doğalgaz terminalleri (LNG) ve endüstriyel tesislerin ısıtma veya soğutma amaçlı kullanılan daha sonra alıcı ortamlara deşarj edilen suları neden olur. Alıcı ortamlara deşarj edilen termal atıksuların en önemli kaynaklarından biri LNG gazlaştırma terminallerinden kaynaklanan soğuk sulardır. Soğuk sular genellikle kıyısal sulara deşarj edilirler. Bu sular deşarj edildikleri alıcı ortamlara göre yoğunluklarının yüksek olması nedeniyle bir çeşit negatif yüzen (batan) jetlerdir. Alıcı ortam canlı türlerine olumsuz etkilerinden dolayı soğuk sular, yüksek seviyede seyrelme sağlayacak şekilde deşarj edilmelidir. Bu çalışmada, yatay olarak deşarj edilen soğuk-yoğun suyun birinci seyrelme ve çarpma noktası gibi bazı deşarj parametreleri laboratuvar ortamında dairesel deşarj portu kullanılarak belirlenmiştir. Soğuk-yoğun atıksuyun alıcı ortam içerisindeki davranışını (jet geometrisini) belirlemek için renk maddesi olarak Rhodamin B ilavesi yapılmıştır. Renklendirilmiş soğuk-yoğun atıksuyun anlık fotoğraflarını çekmek için yüksek çözünürlüklü kamera ve atıksu jet merkezinde meydana gelen sıcaklık değişimlerini (seyrelmeler) ölçmek için de hassas termal problar kullanılmıştır. Farklı atıksu yoğunlukları elde etmek için -3 °C, -5 °C ve -7 °C gibi üç değişik sıcaklık fark değerleri uygulanmıştır. Bu çalışmada elde edilen sonuçlara göre soğuk su deşarjlarının tabana çökme eğilimde olan negatif yüzen (batan) jet gibi davrandığı belirlenmiştir. Ayrıca bu çalışmada, ortalama normalize edilmiş çarpma noktası mesafesi ve birinci seyrelmenin 2.333 ve 0.491 olduğu bulunmuştur.

Anahtar Kelimeler:

Termal kirlilik, Yoğun jet, Soğuk su deşarjı, Birinci seyrelme, Negatif yüzen jet

Determination of some discharge parameters of horizontally discharged cold-dense wastewaters

Thermal pollution is defined as increase or decrease in temperature of an aquatic environment which may be ocean, lake or river by human influence. A common cause of thermal pollution is the use of water as a cooling and heating system by power plants, liquefied natural gas (LNG) re-gasification terminals and industrial manufacturers. One of the important sources of thermal effluents is cold water discharges, which are mainly originated from LNG re-gasification terminals from open cycle heating units. Cold water can be frequently discharged into coastal waters. Due to its high density, cold water discharge is a kind of negatively buoyant jet. Because of some undesired effects of cold water on receiving water species, should be discharged properly into the marine environment with a high level of initial dilution. Some discharge parameters of horizontally discharged cold-dense wastewater such as initial dilutions, impingement points were determined in a laboratory system using circular port in this study. To determine the behavior of the cold-dense wastewater (wastewater jet geometry) Rhodamine B as a colorant was added to the wastewater. A high-resolution camera was used to take snapshots of the colored cold-dense wastewater. Temperature changes (dilutions) in the cold-dense wastewater jet centerline were detected with sensitive thermal probes. To gain different densities, three discharge temperature differences were used as -3 °C, -5 °C and -7 °C. According to the results of this study, it was determined that the cold water discharges behaved like a negative buoyant jet. In addition, it was calculated that the averages of the normalized impingement point and initial dilution of the cold water were found 2.333 and 0.491, respectively.

Keywords:

Thermal pollution, Dense jet, Cold water discharge, Initial dilution, Negatively buoyant jet,

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