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Mathematical modelling and energy conversion efficiency analysis of scroll air motors and its application to a pneumatic-electrical system

Luo, Xing (2011)
Ph.D. thesis, University of Birmingham.

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In industry, pneumatic actuating systems have been widely employed due to their distinct advantages. However, pneumatic actuators have rather low energy efficiency, around 23-30% in general. The work described in this thesis is to study potential strategies for improvement of pneumatic actuator energy efficiency by recovering the exhaust air energy using a scroll-type air motor. The scroll-type air motor is a relatively new technology, and its unique compact structure determines that it can work at high energy efficiency. The mathematical models for vane-type air motors with arbitrary number of vanes and for scroll-type air motors are derived, which cover their thermodynamic process and responses. A complete mathematical model for the pneumatic-electrical system is developed. The simulation studies are carried for initial investigation of the working process for the electrical-pneumatic system and its dynamic responses. A closed-loop control strategy is proved to be essential. An experimental test rig for this system has been built in the laboratory, and the test results are described. The simulation study and the laboratory test results demonstrate that the proposed system is realistic for energy recovery while a proper control strategy is imposed and the overall system energy efficiency can be improved under reasonable constraint conditions.

Type of Work:Ph.D. thesis.
Supervisor(s):Wang, Jihong
School/Faculty:Colleges (2008 onwards) > College of Engineering & Physical Sciences
Department:Department of Electronic, Electrical and Computer Engineering
Additional Information:

Material from this thesis has been published as follows:

1. Wang, J., Yang, L., Luo, X. and Mangan, S. (2010). ‘Mathematical modelling study of scroll air motors and energy efficiency analysis - Part I’, accepted by IEEE/ASME Transactions on Mechatronics, Digital Object Identifier:, U.S.A.

2. Wang, J., Luo, X. Yang, L. Shpanin, L., Jia, N., Mangan, S. and Derby, J.W. (2010). ‘Mathematical modelling study of scroll air motors and energy efficiency analysis - Part II’, accepted by IEEE/ASME Transactions on Mechatronics, Digital Object Identifier:, U.S.A.

3. Luo, X., Wang, J. and Sun, H. (2010). Control and energy efficiency analysis for a pneumatic-electrical system, The Proceedings of the UKACC International Conference on Control 2010, 7-10 September, Coventry, U.K.

4. Luo, X., Sun, H. and Wang, J. (2009). Air leakage study for energy efficiency improvement of a pneumatic-electricity conversion system, The Proceedings of the 15th International Conference on Automation and Computing, 19 September, Luton, U.K.

5. Luo, X., Jia, N., Shpanin, L.M. and Wang, J. (2008). An energy efficient pneumatic-electricity system – modelling study of the scroll expander, The Proceedings of the 11th Mechatronics Forum Biennial International Conference, 23-25 June, Limerick, Ireland.

6. Luo, X., Wang, J., Shpanin, L.M., Jia, N., Liu, G. and Zinober, A. (2008). Development of a mathematical model for vane-type air motors with arbitrary N vanes, The Proceedings of World Congress on Engineering 2008, 2-4 July, London, U.K.

Subjects:TK Electrical engineering. Electronics Nuclear engineering
Institution:University of Birmingham
ID Code:984
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.
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