A solar distillery of essential oils with compound parabolic collectors (CPCs)

Tıbbi ve aromatik bitkilerden su-buhar damıtma yöntemiyle uçucu yağ çıkarmak amacıyla yeni bir uçucu yağ damıtma sistemi geliştirilmiştir. Damıtma sistemi birleşik parabolik toplaçlar ve damıtma ünitelerinden oluşturulmuştur. Birleşik parabolik toplaç ünitesi (BPT), yoğunlaştırma oranı 1.9 ve toplam 3.4 m2 açıklık alanına sahip yedi adet birleşik parabolik toplaçtan imal edilmiştir. Damıtma ünitesi damıtma tankı, yoğuşturucu ve yağ ayırıcıdan ibarettir. Damıtma ünitesi, 5 kg taze bitkiyi damıtmak için boyutlandırılmış ve 5 kg su buharı bitkiden geçirilmiştir. Birleşik parabolik toplaçlar tarafından kazanılan ısı enerjisi damıtma ünitesine transfer edilerek suyun kaynatılması sağlanmıştır. Güneş enerjisinin yetersiz olduğu durumlarda damıtmayı tamamlamak için damıtma tankının altına bir elektrikli ısıtıcı yerleştirilmiştir. Ağustos ayında üç damıtma denemesi gerçekleştirilmiştir. Denemelerin birinde yoğunlaştırılmış güneş ışınımının etkisini belirlemek için birleşik parabolik toplaçların yansıtıcı yüzeyleri siyah bir örtüyle örtülmüştür. Güneş ışınım şiddeti, su, ısı transfer yağı, buhar sıcaklıkları vb. deneysel veriler elektronik olarak toplanmış ve bilgisayarda depolanmıştır. Bulutlanma olmadığında, elektrikli ısıtıcıya ihtiyaç duyulmaksızın ısı transfer yağı sıcaklığı 123 oC'ye yükseldiğinden damıtma başarılı bir şekilde tamamlanmıştır. Bulutlanma olduğunda, damıtma sonuna doğru elektrikli ısıtıcı kullanılmıştır. Güneş ışınımı yoğunlaştırılmadığında ısı transfer yağı sıcaklığı 95 oC'ye yükselmiş ve damıtma suyu elektrikli ısıtıcı kullanarak kaynatılmıştır. Birleşik parabolik toplaçların termal verimliliği %27.9-34.3 arasında değişmiştir

Birleşik parabolik toplaçlı (BPT) güneş enerjili uçucu yağ damıtma sistemi

A new essential oil distillation system was developed to produce the essential oils of medicinal and aromatic plants by water-steam distillation. This distillation system was composed of solar CPCs and distillation units. The solar CPCs unit comprised of seven solar compound parabolic collectors (CPCs), having 3.4 m² aperture area 1.9 concentration ratio. The distillation unit had a distillation tank, a condenser and an oil separator. The distillation unit was sized to distill 5 kg plant material each batch. 5 kg water steam was passed through 5 kg plant pile. The heat gained by solar CPCs was transferred to the distillation unit to boil distillation water. An electrical heater was placed at the bottom of distillation tank to complete distillation processes in case of insufficient solar energy supply. Three distillation trials were conducted in August. One of trials was conducted by covering the CPC reflectors with a black fabric sheet to determine the contribution of concentrating solar irradiance. Experimental data such as solar radiation intensity, temperatures of water, heat transfer oil and steam, etc. were collected and stored in a computer. In case of no clouding, the distillation process was successfully completed since the temperature of heat transfer oil easily increased to 123 °C without needing auxiliary electrical heating. In case of clouding, the electrical heater was switched on in the later period of distillation process. When solar radiation was not concentrated, the temperature of heat transfer oil increased only to 95 °C and the distillation water had to be boiled by electrical heating. The overall thermal efficiency of solar CPCs ranged from 27.9% to 34.3%

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