Membrane processes for heating, ventilation, and air conditioning

Woods, Jason

doi:10.1016/j.rser.2014.01.092

Cited by 180 publications

(55 citation statements)

References 111 publications

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“…In recent reviews, Woods 15 and Zhang 16 provided overviews of the latest membrane developments in HVAC and a summary of potential avenues for future research, while another review by Yang et al 17 highlighted the major advances membrane technology has made in air dehumidification. In search of membranes with the greater selectivity necessary to make this process viable, Zhang et al 18 developed a novel membrane using a polyethersulfone (PES) support layer coupled with a polyvinylalcohol (PVA) active layer, while Bui et al 19,20 later reported the fabrication of a robust hydrophilic PVA/LiCl composite membrane.…”

Section: Introductionmentioning

confidence: 99%

Next-generation HVAC: Prospects for and limitations of desiccant and membrane-based dehumidification and cooling

et al. 2017

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Recently, next-generation HVAC technologies have gained attention as potential alternatives to the conventional vapor-compression system (VCS) for dehumidification and cooling. Previous studies have primarily focused on analyzing a specific technology or its application to a particular climate. A comparison of these technologies is necessary to elucidate the reasons and conditions under which one technology might outperform the rest. In this study, we apply a uniform framework based on fundamental thermodynamic principles to assess and compare different HVAC technologies fromGeneration HVAC: Prospects for and Limitations of Desiccant and Membrane-Based Dehumidification and Cooling," Applied Energy, 200:330-346, 15 August 2017.an energy conversion standpoint. The thermodynamic least work of dehumidification and cooling is formally defined as a thermodynamic benchmark, while VCS performance is chosen as the industry benchmark against which other technologies, namely desiccant-based cooling system (DCS) and membrane-based cooling system (MCS), are compared. The effect of outdoor temperature and humidity on device performance is investigated, and key insights underlying the dehumidification and cooling process are elucidated. In spite of the great potential of DCS and MCS technologies, our results underscore the need for improved system-level design and integration if DCS or MCS are to compete with VCS. Our findings have significant implications for the design and operation of next-generation HVAC technologies and shed light on potential avenues to achieve higher efficiencies in dehumidification and cooling applications.

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Section: Introductionmentioning

confidence: 99%

Next-generation HVAC: Prospects for and limitations of desiccant and membrane-based dehumidification and cooling

et al. 2017

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“…The use of membranes for isothermal dehumidification processes has vast applications in a wide array of industries including heating, ventilation and air conditioning (HVAC) [1,2]; dehydration of flue gas [3][4][5], natural gas [6,7] and organic vapors [8,9]; drying of compressed air [10], steam recovery [9] and air treatment for packaging and processing industries.…”

Section: Introductionmentioning

confidence: 99%

“…Humid air or gas can be dried when it goes through the isothermal filtration setup [1,[11][12][13] as shown in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

Water vapor permeation and dehumidification performance of poly(vinyl alcohol)/lithium chloride composite membranes

Bui

Nida

et al. 2016

Journal of Membrane Science

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a b s t r a c tThin and robust composite membranes comprising stainless steel scaffold, fine and porous TiO 2 and polyvinyl alcohol/lithium chloride were fabricated and studied for air dehumidification application. Higher hydrophilicity, sorption and permeation were observed for membranes with increased lithium chloride content up to 50%. The permeation and sorption properties of the membranes were investigated under different temperatures. The results provided a deeper insight into the membrane water vapor permeation process. It was specifically noted that lithium chloride significantly reduces water diffusion energy barrier, resulting in the change of permeation energy from positive to negative values. Higher water vapor permeance was observed for the membrane with higher LiCl content at lower temperature. The isothermal air dehumidification tests show that the membrane is suitable for dehumidifying air in high humid condition. Additionally, results also indicate a trade-off between the humidity ratio drop with the water vapor removal rate when varying air flowrate.

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“…This is essentially related to the very low moisture transfer coefficient of the common vapor-permeable materials with respect to the associated cost increase, which ultimately lead to an energy recovery device with a long payback time. Most enthalpy heat exchangers make use of a membrane involving the exchange of heat while being permeable to water to guarantee the water vapor transfer [3][4][5]. Among these, ion-exchange membranes (IEM) are particularly attractive because of their effective water transport ability, which is well demonstrated in different fields, including fuel cells, flow batteries, water purification, pharmaceutical industry and the food industry [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Stabilized SPEEK Membranes with a High Degree of Sulfonation for Enthalpy Heat Exchangers

et al. 2018

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Abstract:In this investigation, we explored for the first time the use of cross-linked sulfonated poly (ether ether ketone) (SPEEK) membranes in the fabrication of enthalpy heat exchangers. SPEEK is very sensitive to changes in relative humidity, especially when featuring high degrees of sulfonation (DS), though a poor mechanical stability may be observed in the latter case. Cross-linking is crucial in overcoming this issue, and here, we firstly employed the INCA method (ionomer counter-elastic pressure "n c " analysis) to assess the improvements in the mechanical properties. The cross-link was achieved following a simple thermal-assisted process that occurs directly on the performed membranes. After an initial screening, a degree of cross-link = 0.1 was selected as the better compromise between absorption of water vapor and mechanical properties. When implemented in the enthalpy heat exchanger system, these cross-linked SPEEK membranes enabled a high level of sensible heat exchange, as well as a remarkable variation in the mass (water vapor) transfer between the individual air flows. The performances resulted in being better than those for the system based on a benchmark commercially available perfluorinated Nafion membrane.

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Membrane processes for heating, ventilation, and air conditioning

Cited by 180 publications

References 111 publications

Next-generation HVAC: Prospects for and limitations of desiccant and membrane-based dehumidification and cooling

Next-generation HVAC: Prospects for and limitations of desiccant and membrane-based dehumidification and cooling

Water vapor permeation and dehumidification performance of poly(vinyl alcohol)/lithium chloride composite membranes

Stabilized SPEEK Membranes with a High Degree of Sulfonation for Enthalpy Heat Exchangers

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