Unsteady CHT analysis of a solid state, sensible heat storage for PHES system

Abstract

<jats:sec> <jats:title content-type="abstract-subheading">Purpose</jats:title> <jats:p>The aim of this study is to identify key factors limiting efficiency of pumped heat energy storage systems and determine some general features of transient behavior of solid state, sensible heat storages. Moreover, it aimed at establishing a feasible approach to transient conjugate heat transfer (CHT) analyses for such applications.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Design/methodology/approach</jats:title> <jats:p>A zero-dimensional analytical model is used to determine the system efficiency sensitivity to efficiency of its components. Analysis of argon gas flow in an exemplary configuration of layered bed thermal energy storage is presented. The analysis incorporates a unsteady reynolds averaged navier stokes model with conjugate heat transfer between gas and solid storage core.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Findings</jats:title> <jats:p>It is established that exergetic efficiency of the heat storage is one of the key factors for the system’s overall performance. Three full cycles of storage charging and discharging having 17 h physical time in total are simulated, with calculation of exergetic efficiency for each of the cycles. From standpoint of the system efficiency, it is concluded that the presented heat storage kind has limited exergetic efficiency because of severe temperature drop at the solid–fluid interface in comparison to granular kind of heat storage devices. From the methodological standpoint, it is concluded that calculating the exergetic efficiency of the heat storage by direct computational fluid dynamics (CFD) analysis requires significant amount of walltime and computational resources.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Originality/value</jats:title> <jats:p>The paper presents unconventional approach to using standard CFD tools by exploiting numerical diffusion to numerically suppress high-frequency solution oscillations. This strategy grants that the analysis, otherwise requiring impractically long computation walltime, is completed within a practical time.</jats:p> </jats:sec>

Thermo-structural analysis of a honeycomb-type volumetric absorber for concentrated solar power applications

“…HFF 32,2 outflow temperature at 700°C under steady-state conditions. The corresponding steady-state results can be used as the initial condition for the transient state of a cloud-passing event (Ziegler et al, 2019). Noting that the entire absorber domain is not filled by solid, the factor (1 À w ) is multiplied by the heat source described in equation (2).…”

Meshing strategy for hybrid tet-hex PHES layered bed heat storage

“…Some of the small scale phenomena were filtered out resulting in more uniform flow field. More details on the numerical approach and results of the calculations are presented in [5].…”

Numerical and Experimental Analysis of Heat Transfer for Solid Fuels Combustion in Fixed Bed Conditions

“…Researchers do not relate achieved results of temperature distribution to prepare an in-depth analysis of the heat transfer process in modeled heating devices. The issue of heat transfer phenomenon occurring in a wall neighborhood and free-room of a combustion chamber during fixed-bed combustion still has not been deeply recognized like it is realized in other types of thermal devices used for different industrial applications, like heat treatment furnaces [23][24][25], heat storage systems [26][27][28], or heat exchangers [29][30][31]. So far available results concerned about the packed bed burning assumed a temperature of combustion chamber walls as a boundary condition.…”