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Investigation of cryogenic energy storage for air conditioning applications

Ahmad, Abdalqader Y. H. (2018)
Ph.D. thesis, University of Birmingham.

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This research aims to develop an efficient air conditioning technology that exploits cold energy storage to reduce energy consumption and CO2 emissions and shift the cooling load to off peak times to achieve better national electricity grid stability. The investigation includes the use of commonly used cold storage materials (ice, Phase Change Materials PCM) to enhance the existing air conditioning systems and using cryogenic cold storage namely, liquid nitrogen/air (LN2/Lair) to provide air conditioning for domestic and office buildings. Computational Fluid Dynamic (CFD) modelling of the main two components in the cryogenic cooling system namely, cryogenic heat exchanger and expander were also carried out. An experimental test facility was developed to validate the CFD modelling of the liquid nitrogen evaporation process and assess its potential to provide cooling. Results showed that integrating existing Air Conditioning systems with cold storage tank can lead to energy saving of up to 26% and shifting the cooling load to off peak times, but this energy saving is highly dependent on the storage medium and its storage temperature. Also, using cryogenic fluids (LN2/Lair) to provide air conditioning for domestic and office buildings can recover up to 94% of the energy stored in LAir and up to 78% of the energy stored in LN2, and based on LN2/Lair prices of 3.5 pence per kg the system showed cost saving of the energy consumption of up to 73% when LAir is used and 67% when LN2 is used compared with the conventional system. The CFD modelling of cryogenic heat exchanger showed good agreement with the experimental work with maximum deviation 7.6%.

Type of Work:Ph.D. thesis.
School/Faculty:Colleges (2008 onwards) > College of Engineering & Physical Sciences
Department:School of Mechanical Engineering
Additional Information:

Publications arising from thesis:

Ahmad, A., Al-Dadah, R. and Mahmoud, S., 2016. Liquid nitrogen energy storage for air conditioning and power generation in domestic applications. Energy Conversion and Management, 128, pp.34-43.

Ahmad, A., Al-Dadah, R. and Mahmoud, S., 2016. Air conditioning and power generation for residential applications using liquid nitrogen. Applied Energy, 184, pp.630-640

Ahmad, A., Al-Dadah, R. and Mahmoud, S., 2017. Liquid air utilization in air conditioning and power generating in a commercial building. Journal of Cleaner Production, 149, pp.773-783.

Khalil, K.M., Ahmad, A., Mahmoud, S. and Al-Dadah, R.K., 2017. Liquid air/nitrogen energy storage and power generation system for micro-grid applications. Journal of cleaner production, 164, pp.606-617.

Daabo AM, Mahmoud S, Al-Dadah RK, Ahmad A. Numerical investigation of pitch value on thermal performance of solar receiver for solar powered Brayton cycle application. Energy. 2017 Jan 15;119:523-39

Daabo, A.M., Ahmad, A., Mahmoud, S. and Al-Dadah, R.K., 2017. Parametric analysis of small scale cavity receiver with optimum shape for solar powered closed Brayton cycle applications. Applied Thermal Engineering, 122, pp.626-641.

Badawy T, Hamza M, Ahmad A, Mansour MS, Abdel-Hafez AH, Imam H. New developed burner towards stable lean turbulent partially premixed flames. Fuel. 2018 May 15;220:942-57.

Subjects:TJ Mechanical engineering and machinery
Institution:University of Birmingham
ID Code:8255
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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