Which dimensional model for the analysis of a coated tube adsorber for adsorption heat pumps?

Dias, João M.S.; Costa, V.A.F.

doi:10.1016/j.energy.2019.03.028

Cited by 17 publications

(15 citation statements)

References 38 publications

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“…The results, performed on five replicas, evidenced an average degree of sulfonation of 46.52%. This value is comparable with the DS of virgin S-PEEK polymer (45.43%) performed by the authors [ 13 ] and with the values reported in the literature for the same conditions (48 h of sulfonation, room temperature) [ 30 , 31 , 32 ]. The compatibility of these data suggests the suitability of the proposed synthesis approach potentially also for recycled polymers.…”

Section: Resultssupporting

confidence: 90%

“…The zeolite-binder coating approach is a capable and affordable technology to apply, in an economical way, an adsorbent layer on the heat exchanger module [ 10 , 11 , 12 ]. This allows a higher heat transfer at the coating/metal interface, which reduces cycle time [ 8 , 13 ], but a lower mass transfer due to the presence of the binder and the low porosity of the coating.…”

Section: Introductionmentioning

confidence: 99%

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Sulfonated-Recycled-PEEK as Matrix of Water Vapor Adsorbent SAPO-34 Based Composite Coatings for Adsorption Heat Pumps: Mechanical and Thermochemical Characterization

Palamara

Calabrese

2022

Materials

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In this work, a composite adsorbent coating constituted by high SAPO 34 content and a sulfonated recycled poly (ether ether ketone) was investigated for adsorption heat pump technology. Specifically, the effect of polymer recycling on mechanical and thermal properties, as well as on water vapor adsorption and desorption performance, has been investigated. The degree of sulfonation obtained after 48 h of reaction remained approximately unaltered. The degradation of the polymer due to recycling anticipates the degradation of the C-C bonds of the polymer by about 20 °C without affecting the temperature at which the sulfonic groups degrade. From the mechanical point of view, the coating containing 90% zeolite, due to the use of recycled PEEK, evidenced a worsening of only 11.8% in scratch resistance compared to the virgin one, whereas the adhesive strength exhibited an increase of about 23.2% due to better miscibility of the sulfonated recycled polymer. Adsorption/desorption isobars show an almost similar adsorption capacity of the coating produced with recycled polymer compared to the virgin one, confirming that the water vapor diffusion is not hindered by the polymer matrix during the adsorption/desorption process.

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Sulfonated-Recycled-PEEK as Matrix of Water Vapor Adsorbent SAPO-34 Based Composite Coatings for Adsorption Heat Pumps: Mechanical and Thermochemical Characterization

Palamara

Calabrese

2022

Materials

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“…The adsorber's dynamics are described by a distributed parameter model that considers two dimensions, which is extensively described in [33]. The physical model has already been successfully used for adsorption cooling applications [34].…”

Section: Physical Modelmentioning

confidence: 99%

Modeling and Analysis of a Coated Tube Adsorber for Adsorption Heat Pumps

Dias

Costa

2021

Energies

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This work investigates the effects of several parameters on the coefficient of performance (COP) and the specific heating power (SHP) of a coated-tube adsorber for adsorption heat pumps (AHP) suitable for water heating (space and/or domestic water heating). The COP and SHP are obtained based on physical models that have already been proven to adequately describe this type of adsorber. Several parameters are tested, namely, the regeneration, condenser and evaporator temperatures, the heat transfer fluid velocity, the tube diameter, the adsorbent coating thickness, the metal–adsorbent heat transfer coefficient, and the cycle time. Two different scenarios were tested, corresponding to distinct working conditions. The working conditions for Scenario A are suitable for pre-heating water in mild climates. Scenario B’s working conditions are based on the European standard EN16147. The maximum COP is obtained for regeneration temperatures of 75 °C and 95 °C for Scenarios A and B, respectively. The COP increases for longer cycle times (more complete adsorption and desorption processes) whilst the SHP decreases (less complete cycles by unit time). Hence, the right balance between the COP and the SHP must be found for each particular scenario to have the best whole performance of the AHP. A metal–adsorbent heat transfer coefficient lower than 200 W·m−2·K−1 leads to reduced SHP. Lower adsorbent coating thicknesses lead to higher SHP and can still provide reasonably high COP. However, low coating thicknesses would require a too-high number of tubes to achieve the desired adsorbent mass to deliver the required useful heating power, resulting in too-large systems. Due to this, the best relationship between the SHP and the size of the system must be selected for each specific application.

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“…This work considers a coated tube adsorber module, which was used for heating applications in previous works, and evaluates its performance when used for cooling purposes. The coated tube adsorber is presented as well as a physical model that has already been validated for heating purposes in previous studies (Dias and Costa, 2019;Zhang and Wang, 1999). Analysis of the impact of several governing parameters such as the evaporator, condenser and regeneration temperatures, cycle time, metal-adsorbent heat transfer coefficient (heat transfer coefficient between the outer tube wall and the adsorbent material), metal tube diameter, coating thickness and HTF's velocity on the adsorber's performance is performed.…”

Section: Introductionmentioning

confidence: 99%