Effect of helium xenon as working fluid on the compressor of power conversion unit of closed Brayton cycle HTGR power plant. (20th March 2020)

• Record Type: Journal Article
• Authors: Malik, Adil; Zheng, Qun; Qureshi, Shafiq R.; Zaidi, Asad A.
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 16(2020)
• Page Start: 10119
• Page End: 10129
• Publication Date: 2020-03-20
• Subjects: Closed brayton cycle (CBC) -- Helium compressor -- Helium xenon compressor -- High temperature gas cooled reactor (HTGR); Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.01.220
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Helium is one of the best coolants in closed Brayton cycle power plants as it has superior transport properties; however, the main shortcoming is its compression, which is very difficult to achieve. It leads to a higher number of compressor stages, means bigger mass and big size of the compressor, which create dynamic issues in a compressor of the power conversion unit. All the helium compressors ever constructed have a very high number of stages such as Oberhausen II type 50 MW and JAEA 300 MW, high and low pressure compressors have 25 and 35 stages respectively. In this paper thermodynamic traits of mixing helium with an inert gas xenon were presented. Helium xenon mixture up to the molecular weight of <40 g/mol not only increases heat transfer coefficient but also significantly increase the loading of the compressor. A 7% higher heat transfer coefficient can be achieved with 15 g/mol helium xenon mixture. Therefore, a 15 g/mol helium xenon mixture compressor was designed and its performance analysis conducted using Ansys CFX. It is found that the use of 15 g/mol helium xenon mixture greatly increases the blade loading, which gives a higher total outlet pressure ratio. The obtained results indicated that only 18.75% stages of helium xenon compressor can generate requisite outlet pressure. Hence, the use of helium xenon over pure helium is advantageous as it reduces size and cost of turbo compressor of HTGR power plant. Highlights: He-Xe gas mixture 15 g/mol MW has 7% higher heat transfer coefficient than He. 81.3% lesser stages achieved desired pressure in He-Xe compressor. Compressor of HTGR working on CBC reduced to 3 against 16 stages. Stall margin of He-Xe compressor is reduced compare to He compressor.