• Energy Research
• 2021-2025close

Abstract Solar heating (SH) and radiative cooling (RC) have been regarded as promising clean techniques for thermal energy harvesting and temperature control. However, SH and RC are only a single function of heat collection and dissipation, which means the static device of SH and RC cannot meet the dynamic heat requirement of real-world applications, especially in the daytime. Here, a strategy of dynamic integration of SH and RC is proposed for tunable thermal management. A device (i.e., SH/RC device) that includes a silica cavity, ultrapure single-walled carbon nanotubes (SWCNTs) aqueous dispersion, solar reflective film, and deionized water is designed and fabricated. The outdoor experimental results show that the SH/RC device with SWCNTs media can effectively achieve heat collection with a maximum temperature of 78.9°C, while the SH/RC device with deionized water can achieve heat dissipation. Besides, the temperature modulation ability of the SH/RC device is tested to be 26.3°C and can be theoretically improved to be 60.3°C by improving the solar absorptivity (i.e., 0.9 for SH mode and 0.1 for RC mode) regulation ability of the device and improving its thermal emissivity (i.e., 0.9). Furthermore, annual analysis indicates that the cumulative time in which the SH/RC device temperature is in a comfortable region (i.e., 20°C-26°C) for humans is 60.9% and 30.3% higher than that of the device with individual SH and RC mode. In summary, this work provides alternative thinking for tunable thermal management based on the dynamic utilization of the hot sun and cold universe.

Abstract In this study, a new hybrid solar preheating intercooled gas turbine (SP-IcGT), is presented, in which a parabolic trough solar technology is used to preheat the compressed air before entering the combustor. The performance of the new hybrid gas turbine was evaluated and compared with the conventional hybrid solar preheating gas turbine (SP-GT). Several performance indicators were used in the analysis under Guangzhou (China) weather data. It is observed that the SP-IcGT is superior to the SP-GT system as it can boost the fuel-based efficiency by 19.35% versus 0.26% for the SP-GT system. In addition, the SP-IcGT has a much lower specific fuel consumption (about 7017 kJ/kWh) compared with the 10362 kJ/kWh for SP-GT. The highest fuel-based efficiency of 51.4% is obtained for the SP-IcGT with 47.4% improvement over the SP-GT, which exhibits a levelized electricity cost of 4.58 US/kWh. Meanwhile, fuel consumption and greenhouse gas emissions can be reduced greatly by integrating solar energy with the intercooled gas turbine. The SP-IcGT is more economical than applying carbon capture to the equivalent conventional gas turbine plant combined while achieving the same reduction of CO2 emissions. Overall, the SP-IcGT is an attractive system under different climates.