Analysis of a cascading power cycle without electric pumps for recovering waste heat from vanadium slag. (28th January 2021)

• Record Type: Journal Article
• Authors: Wang, Zixuan; Zhang, Bo; Wang, Liwei; Du, Shuai; Ma, Ruifeng; Zhao, Beibei
• Other Names: Atabani Abdulaziz E. guestEditor.
• Is Part Of: International journal of energy research. Volume 45:Number 6(2021)
• Page Start: 9270
• Page End: 9283
• Publication Date: 2021-01-28
• Subjects: cascade power generation -- pumpless power cycle -- vanadium pentoxide -- waste heat recovery of vanadium slag -- wide temperature range; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.6457
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: In this article, a novel cascading power cycle (CPC) driven by waste heat in a wide temperature range is proposed for promoting the energy grade, heat source recovery rate and cycle performance, which is consisted of a pumpless absorption power cycle and a pumpless organic Rankine cycle, taking ammonia‐water and R245fa as working fluids, respectively. Based on an 800 t/d rotary kiln, the air of 300°C to 350°C from the solid‐gas heat exchanger is recovered for power generation and the calcining process. Gravity‐assisted thermally driven "pump" (GTP) substitutes the conventional electric driven pump to realize "pumpless." The two sub‐cycles are analyzed with the T ‐ s diagram. Moreover, multi‐objective optimization is adopted to obtain an optimal decision by comprehensively considering system efficiency and net work. The optimization results of the CPC‐GTP are concluded as 47.52% exergy efficiency, 130.90 kW total net work, 16.53% thermal efficiency and 82.58% heat recovery rate, with the evaluation index value of 97.01%. Abstract : A cascading power cycle which is driven by waste heat in wide temperature range and consisted of an ammonia‐water sub‐cycle and an R245fa sub‐cycle is proposed. The proposed gravity‐assisted thermally driven "pump" is used to achieve "pumpless" operation. The multi‐objective optimization is adopted to obtain an optimal decision, and the best exergy efficiency and heat recovery rate are 47.52% and 82.58% separately.