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List of KIMM TechnologiesEco-friendly Energy & Environment Research Division

System Configuration and Operation Method of Supercritical CO2 Power Cycle with Improved Exergetic Efficiency Using Both High–temperature Heat Source and Low– temperature Heat Source

Division Eco-friendly Energy & Environment Research Division > Department of Mobility Power Research
Name Dr. Youngmin Kim
Department Department of Engine Research
Tel +82 - 42 - 868 - 7377
E-mail ymkim@kimm.re.kr
Attachment Download 120_System_Configuration_and_Operation_Method_of_Supercritical_CO2_Power_Cycle_with_Improved_Exergetic_Efficiency_Using_Both_High_te.pdf (0.7 KB)

System Configuration and operation method of a supercritical CO2 power cycle that effectively uses the low-temperature heat source to obtain higher output from the same high-temperature heat source



Client / Market

  • Coal-fired power plant, solar power plant, nuclear power plant


Necessity of this Technology

  • Need to improve the efficiency and output and enable load control
  • There is a limit to efficiency improvement as the high-pressure side has a higher specific heat than the low-pressure side in the regenerative heat exchange process of the supercritical CO2 power-cycle.
  • A recompression cycle had been proposed, but the output was reduced due to increased compression work.
  • There is increasing interest for supercritical CO2 power cycle system that could directly utilize different heat sources such as fossil fuel, biofuel, solar heat, nuclear power, and waste heat.
  • There is a difficult with load control for coal-fired power plant or nuclear power plant, therefore, a supercritical CO2 power cycle system needs to be developed, which can improve efficiency from the same heat source and enables load control.


Technical Differentiation

  • By utlilizing low-temperature heat sources like low-temperature waste heat and geothermal heat, high-efficiency generation using high-temperature heat sources like coal-fired power generation, solar power generation, and nuclear power generation can be achieved.
  • For thermal power plant and nuclear power plant, using the same hightemperature heat source, 20% efficiency improvement and 40% load control can be achieved compared to the existing method.
  • The proposed supercritical CO2 power cycle utilizes low-temperature waste heat to obtain 20% higher output and efficiency improvement from the same hightemperature heat source.
  • Compared to the thermal power plant and nuclear power plant that have a difficulty with load control, using the same high-temperature heat source, over 40% load control can be achieved.


Excellence of Technology

  • During the night, the supercritical CO2 cycle operated for partial cooling and the low-temperature waste heat is stored.
  • During the day, stored waste heat is used to run the proposed supercritical CO2 cycle.
  • For example, for nuclear power, the generating output is 358 MWe and the thermal efficiency is 37.6%. During the day, the generating output is 500 MWe, and the thermal efficiency is 52.5%.
  • Using the same heat source, over 40% load control can be achieved.
  • Published a SCI paper: Transcritical or supercritical CO2 cycles using both low- and high-temperature heat sources (Energy 43 (2012), quoted 132 times (as of December 2018))
  • Has several patents and papers on high-efficiency power cycle and energy storage.



Current Intellectual Property Right Status

  • Heat Engine Based on Transcritical Rankine Cycle with Improved Exergy Efficiency and Method Thereof (KR1345106, PCT/KR2012/010664)