Transient Response of Two-Phase Heat Exchanger With Varying Convection Coefficients
- 12 April 2006
- journal article
- Published by ASME International in Journal of Heat Transfer
- Vol. 128 (9), 953-962
- https://doi.org/10.1115/1.2241974
Abstract
Transient changes of fluid and wall temperatures in a two-phase heat exchanger are investigated in this article, particularly with respect to spatial and temporal effects of varying convection coefficients. The coupled energy equations for both sides of the heat exchanger are solved directly with an integral method. Varying convection coefficients are related to changes of vapor fraction between the inlet and outlet of the heat exchanger. Unlike past numerical studies encountering difficulties with instability, stiffness, and lack of convergence, the current integral formulation provides a reliable alternative and efficient procedure for transient response within the heat exchanger. Furthermore, complex inversion from a transformed domain is not needed, in contrast to conventional methods with Laplace transforms. In this article, past integral methods are extended to cases with varying convection coefficients, arising from changes of phase fraction on the two-phase side of the heat exchanger, as well a multiple step-changes of temperature. The predicted results show close agreement with past data, including numerical simulations with a dynamic simulator.Keywords
This publication has 19 references indexed in Scilit:
- Comparison of dynamic performance for direct and fluid coupled indirect heat exchange systemsInternational Journal of Heat and Mass Transfer, 2005
- Transient response of plate heat exchangers considering effect of flow maldistributionInternational Journal of Heat and Mass Transfer, 2005
- Experimental uncertainty of measured entropy production with pulsed laser PIV and planar laser induced fluorescenceInternational Journal of Heat and Mass Transfer, 2005
- Embedded converging surface microchannels for minimized friction and thermal irreversibilitiesInternational Journal of Heat and Mass Transfer, 2005
- Analytic model for transient heat exchanger responseInternational Journal of Heat and Mass Transfer, 2003
- Analytical and experimental response time to flow rate step along a counter flow double pipe heat exchangerInternational Journal of Heat and Mass Transfer, 2001
- Establishing heat–entropy analogies for interface tracking in phase change heat transfer with fluid flowInternational Journal of Heat and Mass Transfer, 2001
- Transient Response of Parallel and Counterflow Heat ExchangersJournal of Heat Transfer, 1992
- Transient Response of the Parallel-Flow Heat ExchangerJournal of Heat Transfer, 1985
- Transient Response of the Counterflow Heat ExchangerJournal of Heat Transfer, 1984