Temperature stratification from thermal diodes in solar hot water storage tank

Rhee, Jinny; Campbell, Andrew R.; Mariadass, Adele; Morhous, Branden

doi:10.1016/j.solener.2009.12.007

Cited by 33 publications

(12 citation statements)

References 8 publications

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“…The partial vacuum within the annulus affects both the above-mentioned operations [9], [21,23]. In the above values, the uncertainties for the measurement of the temperature (± 1 °C) and the pressure (± 2.325 %) have been considered according to the uncertainty analysis in the Apendix.…”

Section: Resultsmentioning

confidence: 99%

“…Pugsley et al [22] have developed a building integrated hybrid solar ICS water heater working on the same principle achieving instantaneous thermal and electrical efficiencies of 60% and 12%, respectively. Rhee et al [23] experimentally measured the temperature stratification in a solar hot water storage tank using a double chimney device that acts as a thermal diode. In the work of Souliotis et al [9] the effective water temperature rise during daily operation and heat retention during nighttime operation, for a device working with respective heat diode mechanisms, was discussed.…”

Section: Introductionmentioning

confidence: 99%

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Integrated collector storage solar water heater under partial vacuum

Souliotis

Papaefthimiou

Caouris

et al. 2017

Energy

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The work focuses on the experimental study of the heat diode mechanism in an Integrated Collector Storage Solar Water Heater (ICSSWH) for domestic applications. The solar device combines a horizontal cylindrical vessel with an asymmetric reflector trough (Compound Parabolic Concentrator-CPC). The cylindrical storage tank comprises two concentric cylindrical vessels: the outer absorbing vessel and the inner storage vessel. The annulus between the cylindrical vessels is partially depressurized and contains a small amount of water serving as Phase Change Material (PCM), which changes phase (mainly at low temperatures) thus producing vapor and creating a thermal diode transfer mechanism from the outer to the inner surfaces of the vessels. Several experimental results, including uncertainty analysis, are demonstrated through diagrams depicting temperature variations, mean daily efficiency and thermal losses coefficient. Additionally results from the variation of the temperature and the total pressure inside annulus are also presented. The results clearly show that the vapor's pressure plays the most important role regarding the thermal performance of the device.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Integrated collector storage solar water heater under partial vacuum

Souliotis

Papaefthimiou

Caouris

et al. 2017

Energy

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“…To minimize the mixing and aid thermal stratification, several designs of storage tanks have been proposed. Stratification is essential to minimize the mixing and thereby affects the harvesting of maximum energy from the collector [68]. To evaluate the performance of stratified storage tanks, several experimental and theoretical studies were conducted for different geometrical designs and operational conditions [69][70][71][72][73][74][75][76][77][78].…”

Section: Storage Tankmentioning

confidence: 99%

An Experimental Study on a Density Driven Solar Water Heating System Using Supercritical CO2 as Working Fluid

Shukla¹

2014

International Journal of Environment and Resource

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An experimental study was performed to investigate the feasibility and performance of thermosyphon solar water heating (SWH) system using R744 (CO2) as the working fluid. The uniqueness of the system was the use of carbon dioxide as a working fluid; which is one of the most promising alternative natural refrigerants. For supercritical carbon dioxide, a small change in temperature or pressure can result in a large change in density, especially close to its critical point. At this pseudo critical region, density decreases rapidly with increase in temperature which aids the thermosyphon flow. An experimental setup in which 1.15 m 2 evacuated tube (U-pipe) solar collector acting as a source as well as an evaporator for the refrigerant, was designed and tested based on this principle. Experimental results have shown that it is possible to induce the natural convective flow even during solar-adverse conditions. Although during winter it was not possible to extract any useful heat gain, the system did show some promising results when operated during spring. The time-averaged collector and heat recovery efficiencies for summer were about 58% and 45%, respectively.

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“…The most up to date, progressive domestic hot water preparation is based on the principle of thermal stratification. It is mainly used to increase the efficiency of solar energy systems and other heat sources by storing hot water in layers in the stratification storage tank [1,2]. Water stored in stratified heat storage tanks, forms naturally, as a result of gravity, layers of different temperature affecting its weight [3].…”

Section: Introductionmentioning

confidence: 99%

Experimental Measurements of Hot Water Stratification in a Heat Storage Tank in Laboratory Conditions

Krafcik

Peráčková

2019

Period. Polytech. Mech. Eng.

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The paper focuses on the experimental measurement of the accumulation of hot water storage with its thermal stratificational thermal layers by means created of elementary conical elements. The basic principle of these elements is the automatic distribution of water temperatures according to temperature and volume flow for a specified time of storage of heat energy. This process involves maintaining the thermal stratification at different height levels of the storage tank, which minimizes the process of balancing the hot water. The aim of the experiments was to demonstrate the thermal energy layering in the 1050 l water storage accumulator in 1 hour depending on the different water flow rates from 250 to 1000 l/h from the heat source.

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Temperature stratification from thermal diodes in solar hot water storage tank

Cited by 33 publications

References 8 publications

Integrated collector storage solar water heater under partial vacuum

Integrated collector storage solar water heater under partial vacuum

An Experimental Study on a Density Driven Solar Water Heating System Using Supercritical CO2 as Working Fluid

Experimental Measurements of Hot Water Stratification in a Heat Storage Tank in Laboratory Conditions

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