Numerical Determination of Comfort Level (PMV/PPD) in an Office Model with Jet Nozzle

Year 2019, Volume: 34 Issue: 3, 207 - 218, 30.09.2019

Alper Yıldırım Coşkun Özalp

https://doi.org/10.21605/cukurovaummfd.638144

Cited By: 1

Abstract

In this study, the air is blown to an office room which has dimensions   3x4x3,5 m by a jet nozzle. Office room includes a human, a refrigerator, a light and a computer, The office conditions were assumed to be in summer in Osmaniye province and the heat loss gain was calculated by considering 100% fresh air flow rate and blowing temperature were found according to this evaluation,. Heat flux is given to the all office walls with heat loss and gain calculation. The velocity and temperature distribution of the jet nozzle are simulated with the ANSYS-FLUENT program. The conservation of mass, the conservation of turbulent momentum, the kinetic energy of the turbulence (k), and the velocity of propagation (ɛ) of the kinetic energy of the turbulence equations are used. The Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD) values at 0.1, 0.6, and 1.1 meters above the ground level of office were calculated from these values. The areas of thermal satisfaction and dissatisfaction in the room were determined with PMV PPD contours. 

Keywords

HVAC, Jet nozzle, PMV, PPD

Jet Lüle ile İklimlendirmesi Yapılan Bir Ofis Modelinde Konfor Seviyesinin (PMV/PPD) Sayısal Olarak Belirlenmesi

Abstract

Bu çalışmada, içerisinde insan, buzdolabı, lamba ve bilgisayar bulunan ve boyutları 3x4x3,5 m olan bir ofise jet lüle ile üfleme yapılmıştır. Ofisin Osmaniye ilinde yaz şartlarında olduğu varsayılmış ve içerisine %100 taze hava verildiği düşünülerek ısı kaybı kazancı hesabı yapılmıştır.  Bu hesaba göre debi ve üfleme sıcaklığı bulunmuştur. Duvarlara, tabana, tavana ısı kaybı ve kazancı hesabına göre ısı akısı verilmiştir. Ayrıca; insan, dolap, lamba ve bilgisayara ısı akısı verilmiştir. Ofise yerleştirilen jet lülenin hız ve sıcaklık dağılımı ANSYS-FLUENT programı ile sayısal olarak elde edilmiştir. Sayısal hesaplamada sürekli koşullarda; kütlenin korunumu, türbülanslı momentumun korunumu, türbülans kinetik enerjisi (k) ve türbülans kinetik enerjisinin yayınım hızı (ɛ) denklemleri kullanılmıştır. Buradan elde edilen değerler ile zeminden 0,1, 0,6, 1,1 metre yüksekliğinde Isıl çevreden memnuniyet (Predicted Mean Vote-PMV) ve Isıl Çevreden Memnuniyetsizlik (Predicted Percentage Dissatisfied-PPD) değerleri hesaplanmıştır. Oluşturulan PMV ve PPD konturlarında jet lüle ile üfleme yapılan oda içerisindeki termal memnuniyet ve memnuniyetsizlik alanları tespit edilmiştir. 

Keywords

HVAC, Jet lüle, PMV, PPD

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