Shell side CFD analysis of a small shell-and-tube heat exchanger

http://nht.xjtu.edu.cn/paper/en/2009208.pdf

3D numerical simulation on shell-and-tube heat exchangers with middle-overlapped helical baffles and continuous baffles – Part I: Numerical model and results of whole heat exchanger with middle-overlapped helical baffles

A three-dimensional, colocated, fully implicit, control volume based calculation procedure, HEATX[1], has been used to simulate fluid flow and heal transfer in shell-and-tube heat exchangers. The three-dimensional numerical model uses the distributed resistance method along with volumetric porosities and surface permeabilities to model the tubes in the heat exchanger. Turbulence effects are modeled using a modified k-ϵ model with additional source terms for turbulence generation and dissipation by tubes. Shell and baffle walk are modeled using the wall function approach. Tubes and baffles are modeled using volumetric porosities and surface permeabilities. Baffle-shell and baffle-tube leakages are modeled using a Bernoulli type formulation. Specialized geometry generators compute baffle, nozzle, and tube region porosities and permeabilities. This article presents the foundation and fluid mechanics of the problem. A subsequent article will discuss modeling of shell-side and tube-side heat transfer. The thre...

Three dimensional numerical simulation of shell-and-tube heat exchangers. Part I: Foundation and fluid mechanics

3D numerical simulation on the shell side heat transfer and pressure drop performances of twisted oval tube heat exchanger

A comparison of four numerical modeling approaches for enhanced shell-and-tube heat exchangers with experimental validation

A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchanges for liquid metal services. For the shellside fluid, the conservation equations of mass, momentum and energy for continuum fluids are modified using the concept of porosity, surface premeability and distributed resistance to account for the blockage effects due to the presence of heat transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, heat transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phased on the shell side and may undergo phase-change in the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reaction (LMFBR) intermediate heat exchanges (IHX) and steam generators (SG). The analytical model predictions are compared with three sets of test data (one for IHX and two for SG) and favorable results are obtained, thus providing a limited validation of the model.

Multidimensional numerical modeling of heat exchangers

Erratum: “Multidimensional Numerical Modeling of Heat Exchangers” (Journal of Heat Transfer, 1982, 104, pp. 417–425)

Improving the room-temperature formability and crystallographic texture of magnesium alloys is essential to their industrial applications. Ca has been reported to affect texture by forming precipitation rather than a solid solution. In the previous study, it was founded that Al_2Ca phase was formed when the Ca was added to the AZ61 magnesium alloy. However, the texture component formed by the Ca phase during deformation was not investigated. Therefore, the effect of Ca precipitation on texture formation was investigated in this study using AZ61 and AZX611 magnesium alloys. High-temperature plain strain compression was conducted at a temperature of 723 K and strain rate of 0.05 s^−1. Al_2Ca contributed to precipitation hardening and induced the PSN effect which is different type of recrystallization in AZX611 with continuous recrystallization occurred in Ca-free alloy. Moreover, newly formed grains showed non-basal texture, and these sub-texture inhibited the development of basal texture during deformation. Graphical abstract

S. M. Cho

Papers

Multidimensional numerical modeling of heat exchangers

Multidimensional numerical modeling of heat exchangers

Erratum: “Multidimensional Numerical Modeling of Heat Exchangers” (Journal of Heat Transfer, 1982, 104, pp. 417–425)

Effect of Ca precipitation on texture development of AZ61 magnesium alloy during high-temperature deformation