BazTech - Yadda

1

Estimation of Solar Energy Availability in Maha Sarakham, Thailand

Chokkuea W., Pattanasethanon S., Suwapaet N., Saengprajak A.

Przegląd Elektrotechniczny

|

2015

|

R. 91, nr 8

118--121

PL

Celem artykułu jest prognozowanie przeciętnych miesięcznych i globalnych możliwości systemu solarnego w Tajlandii w miejscowości Maha Sarakham. Opracowano równania korelacyjne bazujące na modelach Angstroma i Liu-Jordana z indeksem przejrzystości powietrza 0.45 – 0.65 (Angstrom) i 0.30 – 0.95 (Liu-Jordan). Otrzymane równania pozwalają na prognozowanie wydajno sci systemów słonecznych także w innych geograficznych warunkach.

EN

Abstract. Availability of solar energy is crucial for most technological solar applications. The objective of this study is to predict monthly average and global solar radiation patterns on Maha Sarakham horizontal surface of Thailand. Two correlation equations have been successfully developed, one from Angstrom model and the other from Liu-Jordan model, with the minimum and maximum clearness index 0.45 and 0.65 for the equation derived from Angstrom model and 0.30 and 0.95 for the equation derived from Liu-Jordan model. Data of sunshine hours as well as global and diffuse solar radiation was collected at the location and was predicted using equations developed from corresponding models. After validation procedure was conducted, the empirical data was then compared to predicted data. It can be concluded that the developed equations can be used to estimate the diffuse and global solar radiation and also indicate the solar energy availability at Maha Sarakham of Thailand with satisfactory level. This obtained knowledge and information can be applied to other locations with the same geographical conditions as well as used in further researches.

2

Pool boiling of nanofluids on rough and porous coated tubes: experimental and correlation

Cieśliński J. T., Kaczmarczyk T. Z.

Archives of Thermodynamics

|

2014

|

Vol. 35, no. 2

3--20

EN

The paper deals with pool boiling of water-Al2O3 and water-Cu nanofluids on rough and porous coated horizontal tubes. Commercially available stainless steel tubes having 10 mm outside diameter and 0.6 mm wall thickness were used to fabricate the test heater. The tube surface was roughed with emery paper 360 or polished with abrasive compound. Aluminium porous coatings of 0.15 mm thick with porosity of about 40% were produced by plasma spraying. The experiments were conducted under different absolute operating pressures, i.e., 200, 100, and 10 kPa. Nanoparticles were tested at the concentration of 0.01, 0.1, and 1% by weight. Ultrasonic vibration was used in order to stabilize the dispersion of the nanoparticles. It was observed that independent of operating pressure and roughness of the stainless steel tubes addition of even small amount of nanoparticles augments heat transfer in comparison to boiling of distilled water. Contrary to rough tubes boiling heat transfer coefficient of tested nanofluids on porous coated tubes was lower compared to that for distilled water while boiling on porous coated tubes. A correlation equation for prediction of the average heat transfer coefficient during boiling of nanofluids on smooth, rough and porous coated tubes is proposed. The correlation includes all tested variables in dimensionless form and is valid for low heat flux, i.e., below 100 kW/m2.

3

Stopień zatrzymania gazu w półtechnicznych kolumnach air-lift

Dziubiński M., Sowiński J.

Inżynieria Chemiczna i Procesowa

|

2001

|

T. 22, z. 3B

415--420

PL

Wykonano pomiary stopnia zatrzymania gazu dla półtechnicznej kolumny air-lift o cyrkulacji zewnętrznej. Zaproponowano bezwymiarową postać równania korelacyjnego opisującego stopień zatrzymania gazu w póltechnicznej kolumnie air-lift.

EN

Experimental investigation of gas holdup in pilot plant air-lift column were carried out. Correlation equation describing gas holdup have been proposed.