Numerical prediction of the stratification performance in domestic hot water storage tanks

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21220%2F20%3A00340988" target="_blank" >RIV/68407700:21220/20:00340988 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21720/20:00340988

Výsledek na webu

<a href="https://doi.org/10.1016/j.renene.2020.03.090" target="_blank" >https://doi.org/10.1016/j.renene.2020.03.090</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.renene.2020.03.090" target="_blank" >10.1016/j.renene.2020.03.090</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Numerical prediction of the stratification performance in domestic hot water storage tanks

Popis výsledku v původním jazyce

An efficient storage retains thermal stratification and improves the discharging performance. Turbulent mixing between hot and cold water is the prime source of stratification destruction. In this paper quantification of turbulent missing was achieved on the basis of temperature profile, MIX number, and Richardson number. The evaluated parameters include flow rate, ΔT, and diffuser design, henceforth a direct interdependence between each was thus established. Various CFD models were developed and experimentally validated on the test rig in order to find the optimal working conditions in discharge mode. The results proved numerically that the tank working conditions can be optimized by proper selection of inlet device. For instance, slotted type inlet device sustained maximum stratification even in as adverse a condition as of turbulent inflow & low ΔT. Perforated and simple inlet devices were capable of delivering best discharge efficiency only at low flow rate of 200 l/h and were showing insignificant dependency on ΔT. However, as flow rate is increased, ΔT dependency increased. Seeing the compounded benefits of slotted inlet devices and decreased ΔT, it was concluded that slotted inlet device delivered comparatively better thermal performance at both adverse conditions i.e. high flow & low ΔT and high flow & high ΔT, however, failed to outshine the rest of the inlet devices at low flow rate & low ΔT, and low flow rate & high ΔT. These research findings can serve as guidelines to optimize the storage tank design – more specifically, inlet device based design integrated with heating system, as thermal stratification and COP of heating system – heat pumps, for example, are inherently correlated. Heat pumps are high flow rate and low ΔT devices, while, solar systems are low flow rate and high ΔT devices, Thus, opting for accurate choice of inlet device for a particular operating condition is critical.

Název v anglickém jazyce

Numerical prediction of the stratification performance in domestic hot water storage tanks

Popis výsledku anglicky

An efficient storage retains thermal stratification and improves the discharging performance. Turbulent mixing between hot and cold water is the prime source of stratification destruction. In this paper quantification of turbulent missing was achieved on the basis of temperature profile, MIX number, and Richardson number. The evaluated parameters include flow rate, ΔT, and diffuser design, henceforth a direct interdependence between each was thus established. Various CFD models were developed and experimentally validated on the test rig in order to find the optimal working conditions in discharge mode. The results proved numerically that the tank working conditions can be optimized by proper selection of inlet device. For instance, slotted type inlet device sustained maximum stratification even in as adverse a condition as of turbulent inflow & low ΔT. Perforated and simple inlet devices were capable of delivering best discharge efficiency only at low flow rate of 200 l/h and were showing insignificant dependency on ΔT. However, as flow rate is increased, ΔT dependency increased. Seeing the compounded benefits of slotted inlet devices and decreased ΔT, it was concluded that slotted inlet device delivered comparatively better thermal performance at both adverse conditions i.e. high flow & low ΔT and high flow & high ΔT, however, failed to outshine the rest of the inlet devices at low flow rate & low ΔT, and low flow rate & high ΔT. These research findings can serve as guidelines to optimize the storage tank design – more specifically, inlet device based design integrated with heating system, as thermal stratification and COP of heating system – heat pumps, for example, are inherently correlated. Heat pumps are high flow rate and low ΔT devices, while, solar systems are low flow rate and high ΔT devices, Thus, opting for accurate choice of inlet device for a particular operating condition is critical.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20704 - Energy and fuels

Projekt

<a href="/cs/project/LO1605" target="_blank" >LO1605: Univerzitní centrum energeticky efektivních budov – Fáze udržitelnosti</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Renewable Energy

ISSN

0960-1481

e-ISSN

—

Svazek periodika

154

Číslo periodika v rámci svazku

July

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

15

Strana od-do

1165-1179

Kód UT WoS článku

000536955000098

EID výsledku v databázi Scopus

2-s2.0-85082177546