Solar heat storage wall for building ventilation

Stritih, Uroš; Novák, Peter

doi:10.1016/0960-1481(96)88860-4

Cited by 52 publications

(22 citation statements)

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“…Within this project, Ghoneim performed numerical analysis of the following thermal storage mediums: sodium sulfate decahydrate, paraffin, P116-wax, and structural concrete. Following this work, Stritih and Novak (1996) of the University of Ljubljana, Slovenia, analyzed experimentally and with the use of the TRNSYS subroutine a solar wall composed of a transparent thermal insulation material, a thermal storage module/solar collector using paraffinic PCM, and an air channel bringing preheated air to the internal space.…”

Section: Trnsysmentioning

confidence: 99%

Thermal and Energy Modeling of PCM-Enhanced Building Envelopes

Kośny

2015

Engineering Materials and Processes

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Energy storage in building envelopes can be accomplished by means of sensible and latent heat accumulation. Latent heat storage using PCMs has been the focus of multiple building studies, due to its relatively high thermal energy storage capacity per volume, compared to sensible storage available in conventional construction materials. PCM-enhanced building envelopes are widely considered as a prospective building enclosure technology which can help in the near future in peak-hour load reductions and cutting of HVAC energy consumption. Currently, there is a great variety of commercially available PCM products that vary in PCM types (salts, paraffins, fatty acids, etc.) and in packaging and encapsulation options (i.e., PCM pouches, containers, macro-and microencapsulation). In addition, PCMs can be differentiated based on their melting temperatures, which together with PCM location and its quantity, are essential for designing of PCM building envelope applications.Most typically, PCMs used in building envelope applications, need to go through a complete phase transition during 24-h time periods in order to be fully effective. This is why it is critical that the temperature in the location where PCM is installed fluctuates (possibly daily) above and below the PCM functional temperature range. As depicted in Fig. 6.1, the PCM functional temperature range starts usually at the lowest temperature limit of the solidification process. Similarly, it ends at the highest temperature of the melting process.Ideally, the entire heat transported should be available at approximately the same temperature for both, melting and solidification processes. However, in real live, this situation only occurs for the paraffinic PCMs. That is why, for well-designed PCM systems, it is crucial that this temperature range be as narrow as possible. One of the complications is an existence of the temperature hysteresis between PCM melting and solidification. Figure 6.1 depicts a situation when the melting point of a PCM-enhanced material is well above its solidification point. In addition, in most of inorganic and some organic PCMs the supercooling effect can be observed.

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Section: Trnsysmentioning

confidence: 99%

Thermal and Energy Modeling of PCM-Enhanced Building Envelopes

Kośny

2015

Engineering Materials and Processes

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“…Compared with concrete, paraffin-metal mixtures were found to offer a 90 % reduction in storage mass and a 20 % increase in thermal efficiency. Stritih and Novak (1996) investigated a passive solar wall, which absorbed solar energy into a black paraffin wax (with a melting point between 25 and 30°C). The stored heat was used for the space heating with efficiency close to 79 %.…”

Section: Pcm Solar Thermal Storage Wallsmentioning

confidence: 99%

Short History of PCM Applications in Building Envelopes

Kośny

2015

Engineering Materials and Processes

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Ongoing improvements in building envelope technologies suggest that residences will soon be routinely constructed with low heating and cooling loads. The use of novel building materials containing active thermal components (e.g., PCM, subventing, radiant barriers, and integrated hydronic systems) would be an ultimate step in achieving significant heating and cooling energy savings from technological building envelope improvements. The key benefit of using PCM is that it affords structures improved thermal storage capabilities with minimal change to the existing building design (Sharma 2013). The main methods for incorporating PCM into building materials include the use of gypsum plaster boards and other structural boards, blending PCM with thermal insulations, and by macro-packaging. The thermal energy storage property of PCM is based on its latent heat storage capacity, given that large amounts of energy can be stored in a small volume. Therefore, the material containing PCM can absorb and release heat more effectively than conventional building materials. However, the selection of the PCM locations, PCM transition temperature range, and the amount of used PCM are essential for effective and durable use of the PCM-enhanced technologies, considering a relatively long life span of building envelopes.Present-day residential and commercial buildings are becoming more structurally lightweight, and concerns are been raised over indoor thermal comfort due to reduced thermal storage potential. A strong tension exists between the drive to build better efficient structures with less impact on the environment and the tendency to add more mass to the structure for thermal storage. These issues are further heightened by global climate change and the continual rise in energy cost. Without counting traditional arctic ice igloo constructions, the use of PCM in buildings began in the mid-1940s and this passive solar system with thermal storage capability was one of the first applications studied at that time (Telkes 1978;Frysinger and Sliwkowski 1987;. During the 1980s, bulk

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“…Stritih and Novak [12] designed an experimental solar wall for storing the solar heat through the black paraffin wax with a melting temperature range of 25 ~ 30 °C. The stored heat was used for heating and ventilation of a house.…”

Section: A N U S C R I P Tmentioning

confidence: 99%

“…M a n u s c r i p t (12) The relationship between air inlet temperature and air outlet temperature can be described as below [18]:…”

Section: Open Theoretical Modementioning

confidence: 99%

Heating performance of a solar chimney combined PCM: A numerical case study

Liu

2015

Energy and Buildings

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A c c e p t e d M a n u s c r i p t HIGHLIGHTS  The heating performance of the proposed system was numerically studied. Seven design and operating parameters of the proposed system were investigated. The first five parameters need to be carefully selected to maximize the performance. Thermal conductivity of absorber has less impact on the performance of the system.  Inlet air temperature is also an important factor in this study. ABSTRACTAn experimentally validated numerical model is developed to study the effects of seven design and operational parameters on the heating performance of a solar chimney incorporated with phase change material (PCM) in this paper. It is found that when the latent heat increases from 70 to 170 kJ/kg, the melting time is increased by 103% and freezing time is prolonged by 60%. If heat flux is increased by 33%, the melting time is reduced by 36.4%.Increasing thermal conductivity of the insulation material from 0.02 to 0.06 W/m K, the melting time is prolonged by 47.2 %. When absorptivity of the absorber is increased from 0.8 to 1.0, the melting time is decreased by 26.3 %. When transmissivity of the glass cover is increased by 25 %, the melting time is reduced by 26.7%. For the inlet air temperature, when Page 3 of 44 A c c e p t e d M a n u s c r i p t it decreases from 25 to 15 °C, the freezing time is shortened by 39 %. The melting time is only reduced by 8% when thermal conductivity of the absorber is increased by 25 times.Therefore, it can be concluded that the first six parameters have more impact on the system's performance. While the thermal conductivity of absorber slightly impacts it.Keywords: Solar chimney; Phase change material; Heating performance; Numerical study

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Solar heat storage wall for building ventilation

Cited by 52 publications

References 1 publication

Thermal and Energy Modeling of PCM-Enhanced Building Envelopes

Thermal and Energy Modeling of PCM-Enhanced Building Envelopes

Short History of PCM Applications in Building Envelopes

Heating performance of a solar chimney combined PCM: A numerical case study

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