Transient Response of Cross Flow Heat Exchangers Subjected to Simultaneous Temperature and Flow Perturbations

Abstract:

This paper compares the transient thermal performance between counter and parallel cross flow heat exchangers subjected to time varying inlet mass flow rates and inlet temperatures that hasn’t been previously discussed in the available literature. Specifically the transient performance of 2 pass and 3 pass cross flow heat exchangers is discussed in this paper. In the present study the energy balance equations for the hot and cold fluids and the heat exchanger wall were solved using an implicit central finite difference method. Representative values of NTU were considered, and the NTU’s of the heat exchanger were assumed to be uniformly distributed among the heat exchanger passes. Other physically significant parameters such as the capacity rate ratio and the convection heat transfer resistance ratio were systematically varied. A detailed summary based on the observations has been presented.

• Periodical: Applied Mechanics and Materials (Volumes 799-800)
• Pages: 665-670
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.799-800.665
• Online since: October 2015
• Authors: Karthik Silaipillayarputhur*
• Keywords: Flow Perturbations, Multi Pass Cross Flow Heat Exchangers, Temperature, Transient Performance

References

[1] Mishra, M., Das, P.K., and Sarangi, S. 2004. Transient Behavior of Crossflow Heat Exchangers with Longitudinal Conduction and Axial Dispersion, Trans. ASME, J. of Heat Transfer, Vol. 126, pp.425-433.

DOI: 10.1115/1.1738422

[2] Mishra, M., Das, P.K., and Sarangi, S. 2006. Transient behaviour of crossflow heat exchangers due to perturbations in temperature and flow, Int. J. of Heat and Mass Transfer, Vol. 49, pp.1083-1089.

DOI: 10.1016/j.ijheatmasstransfer.2005.09.003

[3] Mishra, M., Das, P.K., and Sarangi, S. 2008. Effect of temperature and flow nonuniformity on transient behaviour of crossflow heat exchanger, Int. J. of Heat and Mass Transfer, Vol. 51, pp.2583-2592.

DOI: 10.1016/j.ijheatmasstransfer.2007.07.054

[4] Silaipillayarputhur, K., and Idem, S. 2011. Step Response of a Single-Pass Crossflow Heat Exchanger with Variable Inlet Temperatures and Mass Flowrates, IMECE2011-62393, Proceedings of IMECE, Denver, CO.

DOI: 10.1115/imece2011-62393

[5] Silaipillayarputhur, K. and Idem, S. 2014. Transient performance model for a multi pass crossflow heat exchanger, Heat Transfer Engineering, Vol. 35, Issue 1, pp.15-24.

DOI: 10.1080/01457632.2013.810082

[6] Silaipillayarputhur, S. and Idem, S., 2014. Transient Performance of Multi-Pass Parallel and Counterflow Crossflow Heat Exchangers, IMECE2014-37030, Proceedings of IMECE, Montreal, Quebec.

DOI: 10.1115/imece2014-37030