Asrori Asrori, S. Suparman, S. Wahyudi, D. Widhiyanuriyawan
{"title":"Investigation of Steam Generation Performance on Conical Cavity Receiver by Different Geometric Concentration Ratios for Fresnel Lens Solar Concentrator","authors":"Asrori Asrori, S. Suparman, S. Wahyudi, D. Widhiyanuriyawan","doi":"10.15587/1729-4061.2020.209778","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.209778","url":null,"abstract":"The paper discusses the comparison of the performance of steam generators in large and small receivers, using a Fresnel lens concentrator. The goal is to get the best value from the efficiency of a steam generator between large and small receivers, with the following task details: a) design a conical cavity receiver that has the most efficient geometric concentration ratio; b) compare the thermal efficiency of conical cavity receivers that have different geometric concentration ratios; c) analyze the potential of the steam energy from the conical cavity receiver produced by the PMMA Fresnel lens concentrator based on the amount of average radiation directly at the study site. The study uses an experimental field research method, which is conducted outdoors. This research was conducted in the energy conversion laboratory, Universitas Brawijaya (Latitude: 7.9553° S and Longitude: 112.6145° W), in September 2019. The PMMA Fresnel lens is used for the solar thermal concentrators. The two receivers with a conical cavity that were compared were made of copper with a volume of 2 litres and 0.25 litres, respectively. They are coated with a glass wool insulator with a thickness of 10 mm. Direct Normal Irradiance (I b ) is measured by a solar power meter. The cup anemometer is used to measure wind speed (v w ) around the receiver. Digi-Sense 12 Channel Scanning Benchtop Thermometer connected to the laptop is used to measure temperature. The positions of the four K-type thermocouples are as follows: 1) ambient temperature (T a ); 2) focal point temperature (T f ); 3) receiver wall temperature (T r ); 4) steam/water temperature (T w ). A pressure gauge to measure the pressure of the steam that goes to the measuring cup was used. After saturation pressure (P sat ) has been reached, it will be known from the condensation process through the copper coil, which functions as a condenser. From the results of the study, the large receivers have specifications CR g =8 and a volume of 2 litres of water. Whereas, the small receiver is CR g =30 and 0.25 L. The large receivers can produce steam latent heat energy Q s =1.37 MJ per cycle with useful efficiency (utilization efficiency) η Th =31.81 %. Whereas the small receiver can produce steam energy, Q s =579.17 kJ per cycle with useful efficiency, η Th =33.31 %. Hence, from the two types of conical cavity receivers, small receivers have that higher effectiveness than large ones can be recommended","PeriodicalId":301695,"journal":{"name":"EnergyRN: Concentrating Solar Power (Topic)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122524554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CFD Analysis on Heat Loss from Solar Cavity Receiver of Parabolic Dish Receiver System","authors":"Pranav Bait, R. Sinha, Priyanka Patil","doi":"10.2139/ssrn.3699517","DOIUrl":"https://doi.org/10.2139/ssrn.3699517","url":null,"abstract":"In a solar cavity receiver the overall efficiency depends on the thermal losses occurring from it. These losses mainly comprises of three types i.e. conduction, convection and radiation. Out of which convection losses constitutes of the majority of these losses. In this paper the CFD software analysis of a cylindrical cavity receiver of length 30 cm and internal diameter 20 cm is carried out to study the temperature variation within the cavity receiver due to heat losses. The analysis is carried out for internal wall temperature of 500K, 1000K, and 1500K. The cavity receiver’s inclination angle varied from 0ͦ, 30ͦ, 45ͦ , 60ͦ to 90ͦ at ambient temperature 293 K.","PeriodicalId":301695,"journal":{"name":"EnergyRN: Concentrating Solar Power (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132944156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Selling Wind","authors":"A. Kakhbod, A. Ozdaglar, Ian Schneider","doi":"10.2139/ssrn.3304189","DOIUrl":"https://doi.org/10.2139/ssrn.3304189","url":null,"abstract":"We offer a parsimonious model to investigate how strategic wind producers sell energy under stochastic production constraints, where the extent of heterogeneity of wind energy availability varies according to wind farm locations. The main insight of our analysis is that increasing heterogeneity in resource availability improves social welfare, as a function of its effects both on improving diversification and on reducing withholding by firms. We show that this insight is quite robust for any concave and downward-sloping inverse demand function. The model is also used to analyze the effect of heterogeneity on firm profits and opportunities for collusion. Finally, we analyze the impacts of improving public information and weather forecasting; enhanced public forecasting increases welfare, but it is not always in the best interests of strategic producers.","PeriodicalId":301695,"journal":{"name":"EnergyRN: Concentrating Solar Power (Topic)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132445026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}