SOLAR POWERED WATER VAPOUR/STEAM EJECTOR CHILLER

摘要

As part of the research project “ProSolar”, a prototype of an innovative solar cooling system withrnwater as the only working fluid was developed. The system produces up to 80 kW chilled water at 12rn℃, used to cool a laboratory building at Karlsruhe University of Applied Sciences. The motive steamrnis provided at 3.7 bar and 140 ℃ by means of direct evaporation in CPC vacuum tube collectors withrna total capacity of 200 kWth. The demonstration plant consists of a double stage steam ejector chiller tornproduce chilled water with sufficient power to cool a building. The system is designed as an openrnprocess, without hydraulic separation between the solar collector field, chiller and cold water pipingrnsystem. In order to bridge short periods of cloudiness, the system is equipped with latent heat storagernwith polyethylene as the main PCM agent and a melting point of approximately 130 ℃. In addition, arnlatent cold storage unit on the basis of a paraffin-water dispersion with a melting point ofrnapproximately 12 ℃ is situated inside the building being capable of providing cooling forrnapproximately 6 hours.rnThe systems’s practical application is two-fold: supplying chilled water during summer time andrnboosting the temperature of the district heating system of the University during the winter. Experiencernfrom the first two years of operation have shown thermal COP’s up to 0.6 (electrical COP up to 9) andrnabout 100 MWh of heating provided over the winter 20014/15.rnThe project consortium consisted of Karlsruhe University of Applied Sciences, Fraunhofer UMSICHTrnand the companies GEA Wiegand and Ritter Group.