İLKNUR ALİBAŞ, Rasim OKURSOY, KAMİL ALİBAŞ

Ispanağın havayla ve suyla ön soğutulmasında kullanılan soğutma sistemlerinin termodinamik hesaplarının belirlenmesi

Bu çalışmada tarladan yeni hasat edilmiş ıspanak (Spinacia oleracea L.) bitkisi havayla ve suyla ön soğutulmuştur. Ön soğutma işlemlerinden önce ürünler 5000 (± 10) gr olacak şekilde tartılarak plastik kasalara yerleştirilmişlerdir. Havayla ve suyla soğutma işlemleri, ürünlerin sıcaklıkları 23°Clik ilk sıcaklık değerinden den 1°Clik depolama sıcaklığına ulaşıncaya kadar sürdürülmüştür. Ön soğutma sistemlerinin her birinde soğutucu akışkan olarak Freon 12 (R 12) gazı kullanılmıştır. Soğutma çevrimine ilişkin Rankine Çevrimine göre çevrimin köşe noktalarını oluşturan basınç (P), hacim (v), sıcaklık (T), entalpi (h), ve entropi (s) değerleri belirlenmiştir. Soğutma sistemlerinin toplam ısısı (soğuk ortamdan kaldırılan ısı) $(Q_{4,1})$ havayla ön soğutma sisteminde 1493.169 kj, suyla ön soğutma sisteminde ise 1829.331 kj olarak bulunmuştur. Ayrıca bu çalışmada, sıcak ortama verilen ısı ($Q_{2}$,3) havayla ön 1620.293 kj, suyla ön soğutma sisteminde ise 1985.074 kj olarak hesaplanmıştır. Kompresöre verilen iş $(W_{1,2})$ ise havayla ön soğutma işleminde 127.124 kj, suyla ön soğutma sisteminde ise 155.743 kj olarak bulunmuştur.

Determination of thermodynamics calculations of precooling systems during hydro and air pre-cooling of spinach

In this study, newly harvested spinach was cooled by air and hydro. Before precooling processes, products were weighed 5000 (± 10) g and placed into plastic boxes. Hydro and air precooling processes were continued until temperature degree of products were reached from 23°C of initial temperature value to 1°C of storage temperature value. Freon12 (R12) was used as cooler liguid in all precooling process. According to Rankine cooling cycle, all values of the corner points of cycle were calculated. Thus, pressure (P), volume (V), temperture (T), entalpy (h) and entropy (S) values were determined. Total heat of the cooling systems (heat removed from the cold environment) $(Q_{4,1})$ was found in this study. Total heat values ranged between 1493.169 kj $h^{-1}$ and 1829.331 kj $h^{-1}$ for air pre-cooling and hydro pre-cooling, respectively. Furthermore, heat scattered to warm environment by consender $(Q_{2,3})$ and action generated by compressor $(W_{1,2})$ values were measured in this study. Heat scattered to warm environment by consender $(Q_{2,3})$ values ranged between 1620.293 kj $h^{-1}$ and 1985.074 kj $h^{-1}$ for air pre-cooling and hydro pre-cooling, respectively. Action generated by compressor $(W_{1,2})$ values ranged between 127.124 kj $h^{-1}$ and 155.743 kj $h^{-1}$ for air pre-cooling and hydro pre-cooling, respectively.

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