Solar Process Cold & Solar Driven Cold Rooms Results from the SOLERA EU project Current Activities in the AgroKühl project Michael Berger, 10 th July, 2012 San Francisco / USA
Two similar projects Recent: Solera EU project with PSE AG/Industrial Solar GmbH Demonstration of solar thermal driven cooling in three different systems One of them in Freiburg with a linear Fresnel collector by Industrial Solar Goals of the system in Freiburg: cooling temperatures below 0 C dry heat rejection latent heat storage (ice storage) cascaded operation of smaller chillers Application: no real application with electrical heaters any pre-defined load profile can be simulated and tested Project was finished in late 2011 Current: AgroKühl project Application: solar driven cold room Industrial Solar as collector supplier System setup is similar to Solera system, but smaller Installation started in March 2012, Commissioning took place last week
Recent Project Linear Fresnel Collector Source: Industrial Solar GmbH
Recent Project Technical Details 132 m² Linear Fresnel Collector was built in Freiburg in 2009 Hybrid System: Operation both possible with pressurised water or in direct steam generation Operation pressures up to 16 bar, temperatures up to 200 C Necessary extension of existing plant: 2 Robur chillers, heat exchanger, electrical load and ice storages planned November 2010, installed in early 2011, commissioned June 2011 Operation and Monitoring since July 2011
Recent Project Technical Details 2 Robur water-ammmonia chillers total cooling power of 24 kw (rated COP th of 0.6) Four Consolar Ice storages total latent heat capacity of 111 kwh (4 x 300 l of water) Eletric heaters as simulated loads total heating power of 0.. 30 kw Heat exchanger for steam operation (2.8 m² heat exchanging area) Steam drum for steam separation (250 l, lamellar separator)
Pressurised water mode: Test Plan Keeping provided temperature at chillers constant: different temperature levels (e.g. 160 C, 200 C), control of active collector area Collector always with maximum power (all mirrors out or all mirrors in) Cooling curve over night (test of heat losses, test of vacua) Compare operation of both chillers with cascaded operation (part load behaviour) Control variable: Temperature at collector exit Actuating variable: Active collector area
Monitoring Results Pressurised Water Hochdorf Date: 2011/09/21 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 T_Collector_out [ C] Volume Flow [l/min] Efficiency [%] Expected Collector Power [kw] 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00 17:30 18:00 Time (GMT +2h) T_Collector_in [ C] Thermal Power [kw] Active Collector Area [m²] DNI [W/m²], right axis 1000 900 800 700 600 500 400 300 200 100 Source: Industrial Solar GmbH 0
Monitoring Results Pressurised Water Freiburg, Date: 2011/09/21 205 200 195 190 185 180 175 170 70 65 60 55 50 45 40 35 30 25 20 T_Collector_out [ C] Active Area [m²] (right axis) T_Collector_in [ C] Volume Flow [l/min] (right axis) 12:00 12:10 12:20 12:30 12:40 12:50 13:00 13:10 13:20 13:30 13:40 13:50 14:00 Thermal Power [kw] DNI [W/m²], right axis Consumed Power (Chillers) [kw] 12:00 12:10 12:20 12:30 12:40 12:50 13:00 13:10 13:20 13:30 13:40 13:50 14:00 Time (GMT +2h) 150 140 130 120 110 100 90 80 950 900 850 800 750 700 650 600 550 500 450 Source: Industrial Solar GmbH
Monitoring Results Pressurised Water SOLERA Subgroup 1, Date: 2011/09/21 60 55 50 45 40 35 30 25 20 15 10 5 Theoretical Optical Efficiency [%] Expected Thermal Efficiency [%] Measured Efficiency [%] 0 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00 17:30 18:00 Time (GMT +2h) Source: Industrial Solar GmbH
Summary and Lessons Learnt Collector Power and Efficiency could be measured in Pressurised water operation, results matched expectations Ice Storages worked well, but heat exchanger properties could be optimised, conclusion may be: Use larger storage only beyond certain charge level, which would have to be defined by economical optimization Chillers showed better part load behaviour in cascaded operation as expected
Current Project: The Cold Room Manufacturer: Kramer GmbH Area: 32 m² Air Volume: 100 m³ Walls: 120mm Polyurethane Sandwich Source: Kramer GmbH Steel Support Structure completely outside
Current Project: The Collector Manufacturer: Industrial Solar GmbH Type: Linear Fresnel Size: 88 m² aperture area Location: rooftop of Kramer s office building Source: Industrial Solar GmbH Operation with pressurised water: 13 bar g ; 180 C
Current Project: The System Chiller: Manufacturer: Robur Spa (Italy) Type: Single-Effect Water-Ammonia 12 kw cooling capacity Rated COP 0.6 Dry heat rejection integrated Storage: Manufacturer: Consolar (Germany) Type: Ice storage (PCM) 2 x 300 l water as latent heat storage 55 kwh latent heat capacity Commissioning: 5th/6th July, 2012 Operation and Monitoring within AgroKühl project in 2012+2013.
Thank you for your attention! www.industrial-solar.de info@industrial-solar.de Emmy-Noether-Str. 2 79110 Freiburg Germany Source: Industrial Solar GmbH