Performance investigation of solar evacuated tube collector using TRNSYS in Tehran

Abstract

Outlet temperature of the collector for efficiency of water-in-glass evacuated tube solar domestic hot water system with natural circulation is generally more than the flat plate collector systems. Additionally, this type of evacuated tube solar collectors with the free circulation is economically cheaper than heat pipes collector systems, this system is widely used in the world. This paper is dedicated to simulation of evacuated tube solar water heating system with natural circulation under the climatic conditions in Tehran city with TRNSYS software. Diagram of the components used in the simulation of the TRNSYS has fully been studied including Type71 for evacuated tube collector with horizontal tank above it with natural circulation and five nodes in the vertically tank stratified in order to control the temperatures out of the collector. Vertical tank increases the tank temperature out of the collector for the household uses. After the simulation we obtain the regression linear curve of the efficiency of the evacuated tube solar domestic hot water system against heat loss of this system in spring and summer seasons with the solar irradiation and mean and ambient temperature in each selected day.

Keywords

• Evacuated Tube; Solar Collector; Thermosyphon Flow; Natural Circulation; Efficiency

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17. ̇ mass flow rate ( ) acceleration due to gravity ( ) tilt angle of evacuated tube collector Subscript ambient temperature , aperture inlet outlet collectible water