Original scientific paper
https://doi.org/10.21278/brod74401
Numerical investigation of multi-nozzle ejector device with inclined nozzles for marine gas turbine
Hong Shi
; College of Energy & Power Engineering, Jiangsu University of Science and Technology
Rentong Zheng
; College of Energy & Power Engineering, Jiangsu University of Science and Technology
Qianwei Zhang
; College of Energy & Power Engineering, Jiangsu University of Science and Technology
Jie Yuan
; Key Laboratory of Aircraft environment control and life support, MIIT, Nanjing University of Aeronautics & Astronautics
Rui Wang
; College of Energy & Power Engineering, Jiangsu University of Science and Technology
Mengmeng Cheng
; College of Energy & Power Engineering, Jiangsu University of Science and Technology
Yitao Zou
; Key Laboratory of Aircraft environment control and life support, MIIT, Nanjing University of Aeronautics & Astronautics
Abstract
The high-temperature exhaust gases and the hot surfaces of the ejector device in marine gas turbines generate significant levels of infrared radiation. An appropriate nozzle structure can effectively lower the exhaust gas temperature and reduce the high-temperature radiation surface area, thereby minimizing external infrared radiation. In this study, a numerical simulation of the nozzle structure in the ejector device was conducted using computational fluid dynamics (CFD) methods. By investigating the orthogonal combinations of nozzle inclination angles and the number of nozzles, the temperature distribution and flow characteristics under different operating conditions were analysed. The results showed that as the nozzle inclination angle increased, the entrainment coefficient (Ce) and the temperature ratio at the inlet and outlet (Rt) initially improved but then worsened. Simultaneously, the pressure loss coefficient (Cpl) increased with the inclination angle. The CRITIC weight method was employed to objectively allocate weights to Rt, Ce, and Cpl, determining the optimal solution. The results indicated that Rt and Cpl had significant and similar weights. The optimal solution was found in Case 10 (α = 5°, x = 4), with corresponding evaluation indices of Ce=2.38, Cpl=11.45, and =0.68. This study's findings are of great importance for enhancing the performance of marine gas turbines and reducing external infrared radiation.
Keywords
ejector; nozzle; CRITIC weight; inclination; marine gas turbine
Hrčak ID:
306591
URI
Publication date:
1.9.2023.
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