Performance improvement of twin-screw air expander used in PEMFC systems by two-phase expansion

Wang, Chuang; Liu, Mingkun; Li, Zengqun; Xing, Ziwen; Shu, Yue

doi:10.1016/j.energy.2023.127249

Cited by 4 publications

(2 citation statements)

References 18 publications

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“…Recently, a notable effort has been directed towards improving expander performance. For instance, Wang et al, in their study, showed that the specific power output of a twin-screw air expander could be increased by 10.8% by adopting two-phase expansion [28]. Apart from the operational optimization of the expander, an improvement in the design aspects of the expander has also been studied.…”

Section: Introductionmentioning

confidence: 99%

An Optimum Design for a Fast-Response Solenoid Valve: Application to a Limaçon Gas Expander

Hossain,

Sultan,

Phung

et al. 2024

Dynamics

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Organic Rankine Cycle (ORC)–based small-scale power plants are becoming a promising instrument in the recent drive to utilize renewable sources and reduce carbon emissions. But the effectiveness of such systems is limited by the low efficiency of gas expanders, which are the main part of an ORC system. Limaçon-based expansion machines with a fast inlet control valve have great prospects as they could potentially offer efficiencies over 50%. However, the lack of a highly reliable and significantly fast control valve is hindering its possible application. In this paper, a push–pull solenoid valve is optimized using a stochastic optimization technique to provide a fast response. The optimization yields about 56–58% improvement in overall valve response. A performance comparison of the initial and optimized valves applied to a limaçon expander thermodynamic model is also presented. Additionally, the sensitivity of the valve towards a changing inlet pressure and expander rotor velocity is analyzed to better understand the effectiveness of the valve and provide clues to overall performance improvement.

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Section: Introductionmentioning

confidence: 99%

An Optimum Design for a Fast-Response Solenoid Valve: Application to a Limaçon Gas Expander

Hossain,

Sultan,

Phung

et al. 2024

Dynamics

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“…They are sometimes called displacement expanders because they take in a fixed amount of fluid and discharge the same after displacing that volume. In recent times, immense effort in the field of positive displacement machines has been directed towards the performance improvement of existing technologies such as screw expanders [20][21][22][23]. Although screw expanders offer better performance compared to similar machines like root blowers, their construction is much more complex [24,25].…”

Section: Introductionmentioning

confidence: 99%

An Optimized Artificial Neural Network Model of a Limaçon-to-Circular Gas Expander with an Inlet Valve

Hossain,

Sultan,

Phung

et al. 2024

Thermo

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In this work, an artificial neural network (ANN)-based model is proposed to describe the input–output relationships in a Limaçon-To-Circular (L2C) gas expander with an inlet valve. The L2C gas expander is a type of energy converter that has great potential to be used in organic Rankine cycle (ORC)-based small-scale power plants. The proposed model predicts the different performance indices of a limaçon gas expander for different input pressures, rotor velocities, and valve cutoff angles. A network model is constructed and optimized for different model parameters to achieve the best prediction performance compared to the classic mathematical model of the system. An overall normalized mean square error of 0.0014, coefficient of determination (R2) of 0.98, and mean average error of 0.0114 are reported. This implies that the surrogate model can effectively mimic the actual model with high precision. The model performance is also compared to a linear interpolation (LI) method. It is found that the proposed ANN model predictions are about 96.53% accurate for a given error threshold, compared to about 91.46% accuracy of the LI method. Thus the proposed model can effectively predict different output parameters of a limaçon gas expander such as energy, filling factor, isentropic efficiency, and mass flow for different operating conditions. Of note, the model is only trained by a set of input and target values; thus, the performance of the model is not affected by the internal complex mathematical models of the overall valved-expander system. This neural network-based approach is highly suitable for optimization, as the alternative iterative analysis of the complex analytical model is time-consuming and requires higher computational resources. A similar modeling approach with some modifications could also be utilized to design controllers for these types of systems that are difficult to model mathematically.

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Potential Evaluation of Twin-Screw Air Expanders with Dual-Lead Rotors Used in PEMFC Systems

Liu,

Wang,

Han

et al. 2024

Applied Sciences

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The reduction in the power cost of air supply systems has emerged as a critical challenge in the development of polymer electrolyte membrane fuel cells. This study proposes the use of dual-lead rotors to improve the performance of twin-screw expanders for the purpose of boosting expanders’ recovery power and consequently lowering the power cost of the air supply subsystem, which is hardly investigated in previous publications. For this purpose, a mathematical model is built to assess the potential of improving the expander performance by means of the dual-lead rotors. And the influence of lead and length of the high-pressure rotor segment and overall rotor length are analyzed. The results demonstrate that the smaller lead and larger length of the high-pressure rotor segment result in better geometric characteristics and thus thermodynamic performance. For example, case #4 with dual-lead rotors exhibits a larger rotating angle at the suction end and a larger suction area than those of constant-lead rotors by 43° and 100%, respectively, which further lower the suction pressure loss. Compared with constant-lead rotors, the maximum increments in the mass flowrate and indicated power are observed as 45% and 25.4%, respectively. However, the dual-lead rotors could not effectively contribute to an increase in the isentropic indicated efficiency of twin-screw expanders due to the severe leakage, and hence, it becomes crucial to address the leakage issues in twin-screw expanders.

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Performance improvement of twin-screw air expander used in PEMFC systems by two-phase expansion

Cited by 4 publications

References 18 publications

An Optimum Design for a Fast-Response Solenoid Valve: Application to a Limaçon Gas Expander

An Optimum Design for a Fast-Response Solenoid Valve: Application to a Limaçon Gas Expander

An Optimized Artificial Neural Network Model of a Limaçon-to-Circular Gas Expander with an Inlet Valve

Potential Evaluation of Twin-Screw Air Expanders with Dual-Lead Rotors Used in PEMFC Systems

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