Dr. Zhen Yang
Concentrated solar power systems in smart grids
Dr. Zhen Yang is a Professor at Tsinghua University, Beijing, China. His research interest includes Thermal Energy Storage, Solar Thermal Power System, Boiling & Condensation, Flow and Heat Transfer in Porous Materials. He has published about 100 peer-reviewed articles in leading journals, including Applied Energy, Energy Conversion and Management, Energy, etc. He was the Keynote Speakers at 2012 Annual Conference of Heat and Mass Transfer of China Society of Engineering Thermophysics and the 6th International conference on cooling and heating technologies (ICCHT2012, Xi’an, China). He served as the Session Chair of the 16th International Heat Transfer Conference (IHTC-16, Beijing, China, 2018), the Technical Member of the 5th International Conference on Renewable Energy Technologies (ICRET 2019, Seoul, South Korea, 2019) and the Scientific Committee Member of the 7th International Symposium on Micro and Nano Technology (Qingdao, China, 2019).
Renewable energy has been regarded as an effective means to solve the energy shortage problem and environmental crisis. Solar energy is the most widespread and abundant renewable energy. The extensive utilization of solar energy can further meet the growing power demand and reduce the consumption of fossil fuels.
Concentrated solar power (CSP) systems are promising technologies to exploit solar energy. Solar collectors are used to concentrate solar energy and turn it into heat. And power cycles are used to accomplish the heat-power conversion process. Thermal energy storage (TES) is necessary for the system to operate continuously even without solar irradiation. The CSP systems with TES can provide a dispatchable power production, as a base load or peak load in smart grids.
During real operating conditions, the CSP systems should adapt to varied solar irradiation and ambient temperature, and meet the changing power demand from smart grids. The operating strategies of the CSP systems under varied conditions are crucial to the application of CSP technologies in smart grids. To make the temperature of heat transfer fluid (HTF) in the storage tank more stable, the mass flow rate of HTF in the solar collectors is adjusted according to the varied solar irradiation. Therefore, the storage tank can provide a hot HTF with constant temperature as heat source for the power cycle. On the heat releasing side of the power cycle, the mass flow rate of the cooling fluid, such as cold water or air, is adjusted to make the minimum temperature of the power cycle remain steady. As for the varied power demand, the sliding pressure operating strategy is adopted, and the operating parameters of the power cycles are cooperatively adjusted.
With more and more CSP systems adopted in smart grids, the intense between the increasing renewable energy production and the decreasing flexibility of the power grids can be effectively alleviated.
Concentrated solar power, Power cycle, Dispatchable power production, Smart grids