Evaluation of thermohydraulic characteristic of printed circuit heat exchangers in pseudocritical region for supercritical CO2 cycle

Currently, 28.2% of the total EU-28 greenhouse gas emissions come from the power sector, a large contributor to greenhouse gas emissions.

Consequently, the emphasis of the research in power generation has swung towards assessing highly efficient and greener power cycles.

In this reference, the novel supercritical carbon dioxide Brayton cycle (sCO2-BC) is an ideal choice that outstrips other formally well-known power cycles (Brayton & Rankine cycles). In sCO2-BC, the role of the pre-cooler is critical. It serves as a sink to the power cycle and regulates the conditions at the compressor's inlet.

The compressor's inlet temperature is intended to be maintained close to the critical temperature of carbon dioxide (CO2) to achieve greater cycle efficiencies.

However, exceptionally higher values of the specific heat capacity of CO2 near its critical point (up to 40 times higher than water) require exceedingly high water flow rates on the cold side to achieve the desired exit temperatures of CO2. Consequently, the pre-cooler's pumping power requirements become high enough to deteriorate the cycle's performance.

This problem can only be mitigated by exploring new channel geometries with enhanced thermohydraulic characteristics.

Therefore, the proposed study plan to characterize the complex thermohydraulic characteristics in the pseudocritical region of CO2 using a multifaceted technique that includes, experimental, numerical, and machine learning techniques.

The proposed work will provide a step forward to the success of sCO2-BC technologies that, in turn, will facilitate its integration with the green energy resources (generation-IV nuclear reactors and solar concentrated plants), helping to meet the EU's 2030 climate and energy framework goals of achieving at least 32% share for renewable energy.