A Combined Cooling and Power System Based on Compressed CO2 Energy Storage

In order to use and storage of greenhouse gas CO2, compressed CO2 energy storage system(CCSE) was designed by using model of Compressed Air Energy Storage(CASE) and with the advantage of high compressibility and big specific heat capacity. The system (CCSE) in question, located in the seaside and consisted of Wind power generator/Compressors/Underground salt cave/Expander and power generator/Refrigeratory for fish, was designed to realize the function of storage wind power and reuse cold energy. When power grid was in low load, such as in the nighttime, power generated from wind was used to compress CO2 from low pressure into high pressure, and CO2 with high pressure was injected into underground salt cave for power grid becoming peak load, then CO2 was withdrew to generate power to peak shaving and generate cold energy to maintain fish refrigerator in low temperature. CO2 carried cold energy have another name as dry ice, solid state of CO2 is easy to preservation and transportation, when transfer the cold energy to fish refrigerator, dry ice become as CO2 in gas phase and flow into another underground salt caves to prepare for next CO2 cycle. Energy efficiency and economic feasibility of the CCSE above was calculated using thermal physics knowledge, and results show that, total energy efficiency exceeds 50%, moreover, the output power price is about 1/3 of peak price when input price is 0.2CHY/kw.h. Key world: CO2 cycle; compressed CO2 energy storage system; wind power storage; cold energy; salt cave;