Solar Ray Collector

OBJECTIVE To deter bite the efficiency of the solar ray collector to a lower place mixed proveal conditions. 1. Illu bitation with halogen lamp. Water temperature ? e? 20C. a) Complete collector b) Collector without render scale 2. Illumination with halogen lamp. Water temperature ? e ? 60C. c) Complete collector d) Complete collector, cold common of song impinges e) Collector without glaze over plate f) Collector without glass plate, cold jet of air impinges INTRODUCTION solar ray collectorstransform solar radiation into hotness and ship that hop up to water. Then solar heat can be used for high temperature water, to back up heating systems.The heart of a solar collector is the absorber, which is usually composed of several narrow metal strips. The carrier fluid for heat transfer flows through a heat-carrying pipe, which is connected to the absorber strip. In plate-type absorbers, two sheets ar sandwiched together allowing the medium to flow mingled with the two sheets. Absorbers are typically made of copper or aluminum. CALCULATION Important formula for figure the serviceable power, PN and efficiency, ? 1. Useful power, PN = c m (? o ? i) where, m = 100 g/min = 1. 667 x 10-3 kg/s c = specific thermal capacity of water = 4. 182 kJ/kg K o = average absorber outlet temperature ?i = average absorber inlet temperature 2. Efficiency, ? = PN / (qi x A) where, qi = 1 kW/m2 A = 0. 12 m2 Sample computing PART A I. Complete collector ( t=15 min ) useable power, PN = c m (? o ? i) = (4. 182 kJ/kg K) (1. 667 x 10-3 kg/s) (32. 5 28. 5) K = 0. 0279 kW efficiency, ? = PN / (qi x A) = 0. 0279kW / (1 kW/m2 x 0. 12 m2) = 0. 232 II. Complete without glass plate ( t=15min ) useful power, PN = c m (? o ? i) = (4. 182 kJ/kg K) (1. 667 x 10-3 kg/s) (35. 0 30. 0) K = 0. 0348 kW efficiency, ? = PN / (qi x A) = 0. 0279kW / (1 kW/m2 x 0. 2 m2) = 0. 29 PART B I. Complete collector ( t=15 min ) useful power, PN = c m (? o ? i) = (4. 182 kJ/kg K ) (1. 667 x 10-3 kg/s) (50. 0 -50. 5) K = 3. 49 W efficiency, ? = PN / (qi x A) = 3. 49W / (1 kW/m2 x 0. 12 m2) = 0. 029 II. Collector without glass plate ( t=10min ) useful power, PN = c m (? o ? i) = (4. 182 kJ/kg K) (1. 667 x 10-3 kg/s) (52. 0 -52. 0) K = 0. 0 W efficiency, ? = PN / (qi x A) = 0. 0 W / (1 kW/m2 x 0. 12 m2) = 0. 0 III. Complete collector, cold jet of air impinges ( t=15 min ) useful power, PN = c m (? o ? i) = (4. 182 kJ/kg K) (1. 67 x 10-3 kg/s) (51. 5-51. 5) K = 0. 0 W efficiency, ? = PN / (qi x A) = 0 W / (1 kW/m2 x 0. 12 m2) = 0. 0 IV. Collector without glass plate , cold jet of air impinges ( t=15min ) useful power, PN = c m (? o ? i) = (4. 182 kJ/kg K) (1. 667 x 10-3 kg/s) (43. 0 49. 0) K = 0. 0418 kW efficiency, ? = PN / (qi x A) = 0. 0418 kW / (1 kW/m2 x 0. 12 m2) = 0. 349 DISCUSSION In this laboratory session, we go conducted an experiment regarding solar Ray Collector. The main idea of this experiment is to determine the effi ciency of the solar ray collector under various experimental conditions.Theoretically, solar collectors transform solar radiation into heat and transfer that heat to a medium (water, solar fluid, or air). Then solar heat can be used for heating water, to back up heating systems. The efficiency of a solar collector is defined as the quotient of operable thermal energy versus received solar energy. Absorbers are usually b lose, as dark surfaces demonstrate a particularly high degree of light absorption. The level of absorption indicates the amount of solar radiation cosmos absorbed that means not being reflected.As the absorber warms up to a temperature higher than the ambient temperature, it gives off a great part of the accumulated solar energy in form of heat rays. From the vary A of the experiment we can observed that the temperature increases for collector with glass is lesser than collector without a glass. This is because for the condition without glass plate, the light emit ted from the halogen lamp not being reflected. Thus the light is emitted directed to the solar ray collector and gives their sufficient efficiency without any disturbance or obstacles.In other scenario, collector with the glass plate, the light that emitted from the halogen lamp is being reflected by the glass plate and also reduced the heat that cross from the glass to the solar collector and thence reduced their efficiency. When the glass is placed, the supreme efficiency recorded was 0. 23 and when the glass is not used the maximum efficiency reached 0. 29. Efficiency indicates how well an energy conversion or transfer process is accomplished. In Part B , we can said that when we use heated water around 60? C, we can agnize that PN and ? ecome constant zero at the end of the time for natural air with glass. This is because the inlet and outlet temperature have become the same. So we can say that there is no useful power in the system. For the experiment that using the blower, the useful power and efficiency of the absorber for the blower without glass plate is higher than blower with glass plate. This is because the air from the blower relieves the heat from the surface of the absorber thus directly reducing the effectiveness of the absorber significantly. There are several error that occurred while we doing the experiment.First is as parallax errors, for instance the reading of the thermometer not taken precisely. Thus it great power be give a slightly error in the data . If the parallax errors occurred, it might influence the results and calculation that we got. Secondly is to get temperature of water at 60 CelsiusC and sometime the temperature drop and affected the heat exchanger. Besides, we are having challengingy in order to maintain the flow rate of 100 cm3/min, because it sometimes goes shovel in and up. Thus we have to check it frequently and its quite disturbing because we also need to take meter for every minutes for 15 minutes.Moreover t he thermometer is not precise because it scale is only 0. 5. Thus it is very difficult to get a correct measurement CONCLUSION In conclusion, we can say that this experiment has gain its objectives since we can determine the efficiency of the solar ray collector under various experimental conditions. In this experiment we can said that, the greater heat losses of the absorber the higher its temperature. Although there a lack of technique in handling the apparatus, we managed to complete the experiment with the guide of instructor.