Project overview

 Objectives of this project:

The overall aim of this project is to explore the underpinning coupled flow and heat transfer mechanismsand characteristics, and to propose an advanced, integrated thermodynamic-heat transfer methodology for the design of optimized supercritical CO₂ (sCO₂) heat exchange systems, which will act to lay a solid theoretical foundation for these flows and enable the development of key technologies that rely on supercritical fluids in a wide range of applications. To reach this aim, the project will focus on three specific objectives: (1) obtain new space and time-resolved data of flow and heat transfer characteristics of sCO2 under the influence of key factors (e.g. gravity) and use this previously-unavailable information to reveal the mechanisms of heat transfer enhancement and deterioration, which corresponds to WP1 (Section 3.1); (2) explore the intrinsic mechanism of flow and heat transfer interactions in supercritical fluid flows, and propose new approaches that can capture this coupling and predict heat transfer enhancement through parameters synergy on both fluid sides; this corresponds to WP2 (Section 3.1); (3) establish a complete design methodology based on the thermodynamic optimization of sCO2 heat-exchange systems, which corresponds to WP3 (Section 3.1). Objective 1 is required to achieve Objective 2, and both objectives are the basis for achieving Objective 3.

Journal Papers in this project:

(1)       Jiangfeng Guo*, Xiulan Huai, Maximizing Electric Power through Spectral-Splitting Photovoltaic-Thermoelectric Hybrid System Integrated with Radiative Cooling, Advanced Science (2023) 2206575. (https://doi.org/10.1002/advs.202206575) )

(2)       Jiangfeng Guo*, Jian Song, Suray Narayan, Konstantin Pervunin, Chrisots Markides, Numerical investigation of the thermal-hydraulic performance of horizontal supercritical CO₂ flows with half-wall heat-flux conditions, Energy 264 (2023) 125845. (https://doi.org/10.1016/j.energy.2022.125845)

(3)       Jiangfeng Guo*, Maximising uninterrupted solar electricity in spectral-splitting photovoltaic-thermal systems integrated with CO2 battery, Journal of Energy Storage 66 (2023) 107402. (https://doi.org/10.1016/j.est.2023.107402)

(4)       Jiangfeng Guo*, Jian Song, Yao Zhao, Konstantin Pervunin, Christos Markides, Thermo-hydraulic performance of heated vertical flows of supercritical CO₂, International Journal of Heat and Mass Transfer 199 (2022) 123437. (https://doi.org/10.1016/j.ijheatmasstransfer.2022.123437)

(5)       Jiangfeng Guo*, Jian Song, Zengxiao Han, Konstantin Pervunin, Christos Markides, Investigation of the thermohydraulic characteristics of vertical supercritical CO₂ flows at cooling conditions, Energy 256 (2022) 124628. (https://doi.org/10.1016/j.energy.2022.124628)

(6)       Zengxiao Han, Jiangfeng Guo*, Xiulan Huai, Theoretical analysis of a novel PCHE with enhanced rib structures for high-power supercritical CO₂ Brayton cycle system based on solar energy, Energy 270 (2023) 126928. (https://doi.org/10.1016/j.energy.2023.126928)

(7)       Zengxiao Han, Jiangfeng Guo*, Xiulan Huai,  Experimental and numerical investigations on thermal-hydraulic characteristics of supercritical CO₂ flows in printed circuit heat exchangers,  International Journal of Thermal Sciences (2023) accepted.

(8)       Xiaokai Liu, Jiangfeng Guo*, Zengxiao Han, Keyong Cheng, Xiulan Huai, Studies on thermal-hydraulic characteristics of supercritical CO₂ flows with non-uniform heat flux in a tubular solar receiver, Renewable Energy 201 (2022) 291-304. (https://doi.org/10.1016/j.renene.2022.10.112)

(9)       Zengxiao Han, Jiangfeng Guo*, Haiyan Liao, Zhongmei Zhang, Xiulan Huai, Numerical investigation on the thermal-hydraulic performance of supercritical CO₂ in a modified airfoil fins heat exchanger, The Journal of Supercritical Fluids 187 (2022) 105643. (https://doi.org/10.1016/j.supflu.2022.105643)

International Academic Conference in this project:

(1)       Jiangfeng Guo*, Jian Song, Konstantin Pervunin, Christos Markides, Heat exchanger arrangements in supercritical CO₂ Brayton cycle systems: an analysis based on the distribution coordination principle, 16th international conference on heat transfer, fluid mechanics and thermodynamics, Amsterdam, Holland, 2022.

(2)       Zengxiao Han, Jiangfeng Guo*, Junlin Chen, Xiulan Huai,  Studies on heat transfer enhancement of supercritical CO2 flows in horizontal tubes with non-uniform heat flux, the 17th International Heat Transfer Conference, 14-18 August 2023, Cape Town, South Africa.

(3)       Jiangfeng Guo*, Jian Song, Christos N. Markides, Studies on intensification mechanism of supercritical co2 flows during heating processes, the 17th International Heat Transfer Conference, 14-18 August 2023, Cape Town, South Africa.

Summary of project results

The CHT-sCO₂ project has achieved its aims in the reporting period in line with Annex 1 to the Grant Agreement. All deliverables and milestones have been completed, which will be presented in the following sections. For the exploitation of the research results in this project, it is divided into several aspects: first, according to the research results of the heat transfer and flow characteristics of the supercritical CO₂ in this project, a new heat transfer enhancement method based on coordinated distributions of parameters is proposed; Secondly, based on this new method, several heat transfer enhancement structures has been developed, which greatly increases the heat transfer performance while the pressure drop does not increase or slightly increases; Thirdly, several thermodynamic systems that are suitable to renewables (like solar power) is proposed by harnessing the unique properties of CO₂. The distributed laws of heat transfer enhancement and deterioration obtained in this project can provide a supplement to the existing theories and provide theoretical support for engineering applications. The developed heat exchanger structure that has been manufactured into an experimental prototype can be applied to the related systems based on supercritical fluids, leading to the improvement of the system’s efficiency and overall compactness. The thermodynamic systems proposed in this project are very suitable for renewables, especially solar power, and is being actively promoted to establish small-scale engineering demonstration in China. The promotion of the research results of this project could not only enrich the relevant theoretical knowledge but also directly be applied in engineering applications, which is conducive to achieving carbon neutrality and mitigating climate change.

Results dissemination

Integrated radiation cooled hybrid solar energy generation technology, https://www.sohu.com/a/644919693_121124715 (In Chinese) 

Effect of Novel PCHE on SCO₂ Power System，https://blog.sciencenet.cn/home.php?mod=space&uid=3562592&do=blog&id=1388448 

Supercritical CO₂ in a modified airfoil fins heat exchanger，https://blog.sciencenet.cn/home.php?mod=space&uid=3562592&do=blog&id=1388407