Tunable LiCl@UiO-66 composites for water sorption-based heat transformation applications

2020 ◽  
Vol 8 (26) ◽  
pp. 13364-13375 ◽  
Author(s):  
Yangyang Sun ◽  
Alex Spieß ◽  
Christian Jansen ◽  
Alexander Nuhnen ◽  
Serkan Gökpinar ◽  
...  
Keyword(s):  
Water Uptake ◽  
Water Sorption ◽  
Coefficient Of Performance ◽  
Cycle Stability ◽  
High Coefficient ◽  
Low Humidity ◽  
Heat Transformation

No deliquescence, cycle stability, increased water uptake over a neat MOF and LiCl at low humidity, and high coefficient of performance.

scholarly journals Ultralow-temperature-driven water-based sorption refrigeration enabled by low-cost zeolite-like porous aluminophosphate

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Zhangli Liu ◽  
Jiaxing Xu ◽  
Min Xu ◽  
Caifeng Huang ◽  
Ruzhu Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Water Sorption ◽  
High Performance ◽  
Global Climate ◽  
Low Cost ◽  
Cost Effective ◽  
High Water ◽  
Coefficient Of Performance ◽  
High Efficient ◽  
Water Based

AbstractThermally driven water-based sorption refrigeration is considered a promising strategy to realize near-zero-carbon cooling applications by addressing the urgent global climate challenge caused by conventional chlorofluorocarbon (CFC) refrigerants. However, developing cost-effective and high-performance water-sorption porous materials driven by low-temperature thermal energy is still a significant challenge. Here, we propose a zeolite-like aluminophosphate with SFO topology (EMM-8) for water-sorption-driven refrigeration. The EMM-8 is characterized by 12-membered ring channels with large accessible pore volume and exhibits high water uptake of 0.28 g·g−1 at P/P0 = 0.2, low-temperature regeneration of 65 °C, fast adsorption kinetics, remarkable hydrothermal stability, and scalable fabrication. Importantly, the water-sorption-based chiller with EMM-8 shows the potential of achieving a record coefficient of performance (COP) of 0.85 at an ultralow-driven temperature of 63 °C. The working performance makes EMM-8 a practical alternative to realize high-efficient ultra-low-temperature-driven refrigeration.

scholarly journals SISTEM KONTROL SUHU PENYIMPAN BUAH-SAYUR PADA MESIN PENDINGIN TERMOELEKTRIK

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Rofan Aziz ◽  
Muh Tanwirul Afkar ◽  
Sunanto Sunanto ◽  
Karsid Karsid
Keyword(s):  
Control System ◽  
Temperature Control ◽  
Fruits And Vegetables ◽  
Coefficient Of Performance ◽  
Temperature Control System ◽  
Vapor Compression ◽  
Cooling Systems ◽  
High Coefficient ◽  
Conventional Cooling ◽  
Vapor Compression Cooling

Conventional cooling systems based on vapor compression have a high coefficient of performance (COP). However shortage of vapor compression cooling systems still using refrigerants that have detrimental effects on the environment. For that purpose, the research of fruit and vegetable storage machine using thermoelectric system TEC1-12706 with temperature control system using arduino. In this study the temperature in the cabin can be stable at 15° C and still feasible for use as a storage of fruits and vegetables.

scholarly journals Multi-spin counter-diabatic driving in many-body quantum Otto refrigerators

Quantum ◽  
2020 ◽  
Vol 4 ◽  
pp. 377
Author(s):  
Andreas Hartmann ◽  
Victor Mukherjee ◽  
Glen Bigan Mbeng ◽  
Wolfgang Niedenzu ◽  
Wolfgang Lechner
Keyword(s):  
Finite Time ◽  
System Size ◽  
Scaling Behavior ◽  
Catalytic Process ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Many Body ◽  
Promising Candidate ◽  
High Coefficient

Quantum refrigerators pump heat from a cold to a hot reservoir. In the few-particle regime, counter-diabatic (CD) driving of, originally adiabatic, work-exchange strokes is a promising candidate to overcome the bottleneck of vanishing cooling power. Here, we present a finite-time many-body quantum refrigerator that yields finite cooling power at high coefficient of performance, that considerably outperforms its non-adiabatic counterpart. We employ multi-spin CD driving and numerically investigate the scaling behavior of the refrigeration performance with system size. We further prove that optimal refrigeration via the exact CD protocol is a catalytic process.

High Coefficient of Performance Quantum Well Thermoelectric Nano Cooler

2007 ◽  
Author(s):  
Velimir Jovanovic ◽  
Saeid Ghamaty ◽  
Daniel Krommenhoek ◽  
John C. Bass
Keyword(s):  
Thin Film ◽  
Quantum Well ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Room Temperature ◽  
Single Stage ◽  
Coefficient Of Performance ◽  
High Coefficient ◽  
Temperature Detector ◽  
Good Agreement

Nanotechnology quantum well thermoelectric materials have been developed that have high Figures of Merit and that can attain very high coefficients of performance (COP) to satisfy the requirements for cooling room temperature detectors. Hi-Z Technology, Inc. (Hi-Z) has developed Si/SiGe solid state quantum well (QW) thermoelectric (TE) materials that have demonstrated a Seebeck coefficient and thermoelectric properties that provide >4X higher conversion efficiencies than the current bulk TE materials. With the new Si/SiGe QW materials, cooling systems can be designed that are much smaller, quieter, lighter weight, and that have much reduced power requirements than current TE materials or presently used vapor-compression systems. On-going development for these new QW TE materials has demonstrated high-efficiency TE materials for power generation applications ranging from providing power for wireless sensors to converting waste heat from diesel engine exhaust directly to electricity and thus reducing the load on the alternator and reducing fuel consumption. Now, cooling devices with a high coefficient of performance (COP) are feasible and are being designed for room temperature detector cooling applications. Multi-layer nanocomposite QW films (each 10 nm thick) were fabricated to demonstrate that Si/SiGe QW materials can be deposited on a low thermal conductivity substrate and provide at least the desired COP over the required temperature range of 250K to 350K in a single-stage nano cooler. These QW thermoelectric materials can also be implemented into commercial equipment in the air conditioning and refrigeration applications, thus eliminating fluids, ozone-impacting refrigerants and compressors. Thermoelectric properties of QW thin-film materials have been measured at Hi-Z, several universities and national labs. The conversion efficiency of QW materials has been measured at Hi-Z in two different test couples and in a two-couple device. In all cases, good agreement was obtained between the measurements and prior analytical predictions. Cooling performance was measured in a test with one QW TE element and good agreement was obtained between measurements and analytical predictions. TE properties of the Si/SiGe QW material used in the analysis and design of the subject TE nano cooler were recently independently verified at University of California San Diego (UCSD) and the U.S. National Institute of Standards and Technology (NIST). This paper deals with the analysis of a high COP QW TE single-stage nano cooler for room temperature detectors and with the improved TE properties obtained with the QW thin-film materials resulting in such high COP designs.

Modifications in Water Sorption Isotherms of Cement Mortars Caused by Carbonation: Effects of Cycles

2014 ◽  
Vol 1042 ◽  
pp. 3-9 ◽  
Author(s):  
Son Tung Pham
Keyword(s):  
Calcium Carbonate ◽  
Water Sorption ◽  
Coupling Effect ◽  
Sorption Isotherms ◽  
Adsorbed Water ◽  
Size Distributions ◽  
Cement Mortars ◽  
Pore Size Distributions ◽  
Low Humidity ◽  
Water Sorption Isotherms

This work aimed to examine the influence of carbonation on the water sorption isotherms of cement materials. Two types of normalized CEM I and CEM II Portland cement mortars were carbonated at 20°C, 65% relative humidity and 20% of CO2concentration for 32 days. The pore size distributions determined from the water sorption showed a reduction in microporosity and a slight increase in the mesoporosity. The pores clogging due to formation of calcium carbonate was highlighted by the reduction of the quantity of adsorbed water and the decrease in the hysteresis isotherms. We also studied the coupling effect between carbonation and humidification-drying cycles. The results of this study also indicated that the humidification-drying cycles coincide only from the second cycle because of a difficult evacuation of water during desorption, even at low humidity.

scholarly journals Water and methanol adsorption on MOFs for cycling heat transformation processes

2014 ◽  
Vol 38 (5) ◽  
pp. 1846-1852 ◽  
Author(s):  
Felix Jeremias ◽  
Dominik Fröhlich ◽  
Christoph Janiak ◽  
Stefan K. Henninger
Keyword(s):  
Low Temperature ◽  
Water Uptake ◽  
High Water ◽  
Heat Pumps ◽  
Uptake Capacity ◽  
Water Uptake Capacity ◽  
Temperature Heat ◽  
Thermally Driven ◽  
Heat Transformation ◽  
Transformation Processes

MOFs with high water uptake capacity and hydrothermal stability are gaining attention for low temperature heat transformation applications such as thermally driven adsorption chillers or adsorption heat pumps.

scholarly journals New Composite Water Sorbents CaCl2-PHTS for Low-Temperature Sorption Heat Storage: Determination of Structural Properties

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
Alenka Ristić ◽  
Nataša Zabukovec Logar
Keyword(s):  
Electron Microscopy ◽  
Calcium Chloride ◽  
Structural Properties ◽  
Sorption Capacity ◽  
Water Uptake ◽  
Water Sorption ◽  
Heat Storage ◽  
Impregnation Method ◽  
Sorption Heat ◽  
Water Sorption Capacity

Sorption heat storage, as one of low-energy consuming technologies, is an approach to reduce CO2 emissions. The efficiency of such technology is governed by the performance of the applied sorbents. Thus, sorbents with high water sorption capacity and regeneration temperature from 80 to 150 °C are required. Incorporation of hygroscopic salt such as calcium chloride into porous materials is a logical strategy for increasing the water sorption capacity. This work reports the study on the development of composites with PHTS (plugged hexagonal templated silicate) matrix with an average pore size of 5.7 nm and different amounts of calcium chloride (4, 10, 20 wt.%) for solar thermal energy storage. These composites were prepared by wetness incipient impregnation method. Structural properties were determined by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). CaCl2 was confined in micro- and mesopores of the matrix. The resulting CaCl2-PHTS materials were used for water sorption at 40 °C, showing an increase of maximal water uptake with higher amount of calcium chloride from 0.78 g/g to 2.44 g/g of the dry composite. A small reduction in water uptake was observed after 20 cycles of sorption/desorption between temperatures of 140 °C and 40 °C, indicating good cycling stability of these composites under the working conditions.

Oscillatory Water Sorption Test for Determining Water Uptake Behavior in Bread Crust

2007 ◽  
Vol 55 (7) ◽  
pp. 2611-2618 ◽  
Author(s):  
Neleke H. van Nieuwenhuijzen ◽  
R. Hans Tromp ◽  
Rob J. Hamer ◽  
Ton van Vliet
Keyword(s):  
Water Uptake ◽  
Water Sorption ◽  
Bread Crust

scholarly journals Steady-State Investigation of Carbon-Based Adsorbent–Adsorbate Pairs for Heat Transformation Application

2020 ◽  
Vol 12 (17) ◽  
pp. 7040 ◽  
Author(s):  
Faizan Shabir ◽  
Muhammad Sultan ◽  
Yasir Niaz ◽  
Muhammad Usman ◽  
Sobhy M. Ibrahim ◽  
...  
Keyword(s):  
Isosteric Heat ◽  
Coefficient Of Performance ◽  
Performance Parameters ◽  
Concentration Difference ◽  
Cooling Performance ◽  
Wide Range ◽  
R 134A ◽  
Heat Transformation ◽  
Adsorption Cycle ◽  
The Ideal

In this study, the ideal adsorption cycle behavior of eight activated carbon and refrigerant pairs is evaluated. The selected pairs are KOH6-PR/ethanol, WPT-AC/ethanol, Maxsorb-III/methanol, Maxsorb-III/CO2, Maxsorb-III/n-butane, Maxsorb-III/R-134a, SAC-2/R32 and Maxsorb-III/R507a. The following cooling performance parameters are evaluated for all pairs: specific cooling energy (SCE), concentration difference (ΔW) and coefficient of performance (COP) of ideal adsorption cooling and refrigeration cycles. The evaporator temperatures for the applications of adsorption cooling and refrigeration are selected as 7 and −5 °C, respectively. It is found that the Maxsorb-III/methanol pair has shown the highest specific cooling energy and coefficient of performance in a wide range of desorption temperatures; i.e., for the adsorption cooling cycle it has SCE and COP of 639.83 kJ/kg and 0.803, respectively, with desorption temperatures of 80 °C. The KOH6-PR/ethanol and the WPT-AC/ethanol pairs also give good performances comparable to that of the Maxsorb-III/methanol pair. However, the SAC-2/R32 pair possesses a higher concentration difference than the Maxsorb-III/methanol, KOH6-PR/ethanol and WPT-AC/ethanol pairs but shows a lower performance. This is due to the lower isosteric heat of adsorption of SAC-2/R32 compared to these pairs. It is found that Maxsorb-III/methanol, KOH6-PR/ethanol and WPT-AC/ethanol are the most promising pairs for application in designing adsorption cooling and refrigeration systems.

Greenhouse heating using heat pumps with a high coefficient of performance (COP)

2010 ◽  
Vol 106 (4) ◽  
pp. 405-411 ◽  
Author(s):  
Y. Tong ◽  
T. Kozai ◽  
N. Nishioka ◽  
K. Ohyama
Keyword(s):  
Heat Pumps ◽  
Coefficient Of Performance ◽  
High Coefficient
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