Experimental and theoretical analyzing of cylindrical trough type solar concentrator

EXPERIMENTAL AND THEORETICAL ANALYZING OF CYLINDRICAL TROUGH TYPE SOLAR CONCENTRATOR SUMMARY Key words: Solar energy, cylindrical reflector, absorber, hot water and superheated steam In an experimental setup in Denizli steam is generated with a cylindrical mirror which has fixed and flat absorber and a system that traces the sun. The mirrors which have 4.2 m width and 13 m length and total area of 54 m2 are placed on two axes. The sunrays are sent to the absorber with a focus length of 12 meter from these mirrors which collect and concentrate sunrays. The collector's concentration rate is 20. The absorber's width is 0.20 m and length is 14 m and has a area of 2.8 m2. The experimental set up is placed to the south and traces the sun east to west direction. Because it is placed with the same inclination with area latidute (37°), it is a polar system. The fluid which is circulated in the experimental setup to generate electricity is water which is obtained by condensing the steam that is used in turbines. This water's corrosion properties are better. By focusing of the sunrays that reflects from cylindrical mirrors at absorber, the water is converted to heated water or superheated steam. Because the steam generation is depended on sunrays the pumping of the water is made by a mass flow regulator automatically. The obtained superheated steam is again returned to the system after removing it's heat in a heat exchanger. In the test, ambient temperature, wind speed, ambient humidity, input and output temperatures, sun radiation and mass flow of steam is measured. The heated water, and steam are generated at different days. In the test for generating steam with different pressures, heated with constant mass flow, heat power and efficiency is found and the results are compared. In different times, heated water and steam is generated. The experimental works showed that the system has %40 heat efficiency. Because the power is depend on radiation, in the morning and evening hours the minimum value of power 6 kW and between 1 1:30 and 13:30 hours (noon hours) heat power of 15 kW is obtained. Although there isn't much difference in the heat efficiency of heated and superheated water and steam, the heat efficiency of steam is greater. Thus the works about producing electricity with steam is written and it is stated that electricity can be produced by this system that generates directly steam. Because the maximum heat loss occurs in the absorber, the total heat conductivity constant in the absorber is found. For evaluating the analyses of the heat power and efficiency, the diagrams of experiments conducted on different days are prepared and compared. In addition to improve the performance of the system is investigated. xv