Wang Xing

Bio: Wang Xing is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Compressed air energy storage & Turbine. The author has an hindex of 4, co-authored 21 publications receiving 48 citations.

Experimental and Numerical investigation of closed Radial-Inflow Turbine with Labyrinth Seals

Abstract: It is a common practice to use closed impeller in radial inflow turbine against the flow leakage from tip clearance of impellers, especially in small volume flow condition. It utilizes labyrinths between the shroud and the case to abate the higher pressure leakage. Experimental and computational investigations of shroud clearance flow in a radial inflow turbine with labyrinth seals are presented in this paper. Compared with the result without leakage, numerical computation result including the leakage of labyrinth seals agrees better with that of the experiment result, which indicates that the leakage of labyrinth seals cannot be neglected. Several geometrical arrangements with a series of different clearance of labyrinth seals are investigated experimentally and numerically, and the dimensionless shroud clearance is of 0%, 0.6%, 1.2%, 1.8%, 2.7%, 3.6%. Finally, the character of flow and loss is analyzed by computational fluid dynamics (CFD) tools. The results indicate that the labyrinth seal flow has no effect on the main flow passage and mainly causes different leakage mass flow.

Flow characteristic of a multistage radial turbine for supercritical compressed air energy storage system

Abstract: Compressed air in supercritical compressed air energy storage system expand from supercritical to atmospheric conditions at lower inlet temperature (<500 K) to generate MW scale power. Therefore, a...

Flow analysis and performance improvement of a radial inflow turbine with back cavity under variable operation condition of compressed air energy storage

Abstract: In present study, the effect of back cavity in a radial inflow turbine is investigated numerically. The size effect of labyrinth seal clearance is revealed. The performances of radial turbine with back cavity at different total expansion ratio are also investigated. Results illustrate that the clearance variation of original labyrinth seal in back cavity has limited effect on the leakage flow and the isentropic efficiency. The existence of back cavity reduces the isentropic efficiency at every total expansion ratio, and a maximum isentropic efficiency reduction of 1.5% is obtained when total expansion ratio is 2.89. To control the rotor‐back cavity coupling flow loss, a “rotor‐back cavity seal” is also proposed, and the isentropic efficiency of radial turbine is significantly improved at different total expansion ratio.

Boundary Layer Theory

Abstract: The boundary layer equations for plane, incompressible, and steady flow are $$\matrix{ {u{{\partial u} \over {\partial x}} + v{{\partial u} \over {\partial y}} = - {1 \over \varrho }{{\partial p} \over {\partial x}} + v{{{\partial ^2}u} \over {\partial {y^2}}},} \cr {0 = {{\partial p} \over {\partial y}},} \cr {{{\partial u} \over {\partial x}} + {{\partial v} \over {\partial y}} = 0.} \cr }$$

Cyclic transient behavior of the Joule–Brayton based pumped heat electricity storage: Modeling and analysis

Abstract: Pumped heat electricity storage (PHES) has the advantages of a high energy density and high efficiency and is especially suitable for large-scale energy storage. The performance of PHES has attracted much attention which has been studied mostly based on steady thermodynamics, whereas the transient characteristic of the real energy storage process of PHES cannot be presented. In this paper, a transient analysis method for the PHES system coupling dynamics, heat transfer, and thermodynamics is proposed. Judging with the round trip efficiency and the stability of delivery power, the energy storage behavior of a 10 MW/4 h PHES system is studied with argon and helium as the working gas. The influencing factors such as the pressure ratio, polytropic efficiency, particle diameters, structure of thermal energy storage reservoirs are also analyzed. The results obtained indicate that, mainly owing to a small resistance loss, helium with a round-trip efficiency of 56.9% has an overwhelming advantage over argon with an efficiency of 39.3%. Furthermore, the increases in the pressure ratio and isentropic efficiencies improve the energy storage performance considerably. There also exit optimal values of the delivery compression ratio, particle sizes, length-to-diameter ratios of the reservoirs, and discharging durations corresponding to the maximum round-trip efficiency and preferable discharging power stability. The above can provide a basis for the optimal design and operation of the Joule–Brayton based PHES.

A review of compressed-air energy storage

Abstract: Due to the high variability of weather-dependent renewable energy resources, electrical energy storage systems have received much attention. In this field, one of the most promising technologies is compressed-air energy storage (CAES). In this article, the concept and classification of CAES are reviewed, and the cycle efficiency and effective energy are analyzed in detail to enhance the current understanding of CAES. Furthermore, the importance of the real-gas properties of air is discussed. Related research on adiabatic CAES and isothermal CAES is also presented.Due to the high variability of weather-dependent renewable energy resources, electrical energy storage systems have received much attention. In this field, one of the most promising technologies is compressed-air energy storage (CAES). In this article, the concept and classification of CAES are reviewed, and the cycle efficiency and effective energy are analyzed in detail to enhance the current understanding of CAES. Furthermore, the importance of the real-gas properties of air is discussed. Related research on adiabatic CAES and isothermal CAES is also presented.