Negative thermal-flux phenomenon and regional solar absorbing coating improvement strategy for the next-generation solar power tower

Qiliang Wang, Junchao Huang, Zhicheng Shen, Yao Yao, Gang Pei, Hongxing Yang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)

Abstract

Solar power tower (SPT) is regarded as the most promising technology for applications in concentrating solar power. However, a significant decrease in the solar-thermal conversion efficiency of the tower receiver in the SPT system occurs at high operating temperatures due to the massive radiation heat loss caused. In this work, a detailed heat transfer model of the tower receiver was established, and the negative thermal-flux phenomenon was discovered in the tower receiver based on the verified simulation results. In this context, a novel improvement strategy for regional solar absorbing coating on the tower receiver was proposed to enhance the thermal performance of the tower receiver in the next-generation SPT system. Two kinds of novel tower receivers by changing conventional solar absorbing coating into the silver-based coating (novel receiver I) and black chrome-based coating (novel receiver II) at negative thermal-flux regions were proposed, investigated, and compared with the prototype tower receiver without changes. The overall thermal performance of three kinds of tower receivers was numerically analyzed under different solar irradiances, solar hours throughout the day, and seasons. The results demonstrated that both the novel tower receivers achieved breakthrough enhancements on the thermal performance compared with the prototype receiver, showing great potential for practical application. The negative thermal-flux regions accounted for almost a quarter of the entire receiver surface. The annual average radiation heat losses from negative thermal-flux regions in the novel receivers I and II were effectively reduced by 93.00 and 53.14%. Accordingly, the annual average heat gains and receiver efficiencies were significantly enhanced by 6.54 and 6.03%, respectively.

Original languageEnglish
Article number114756
JournalEnergy Conversion and Management
Volume247
DOIs
Publication statusPublished - 1 Nov 2021

Keywords

  • Concentrating Solar Power (CSP)
  • Heat transfer
  • Molten salt
  • Solar absorbing coating
  • Solar Power Tower (SPT)

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

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