scholarly journals Performance Investigation of a Two-Bed Type Adsorption Chiller with Various Adsorbents

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2553 ◽  
Author(s):  
Jung-Gil Lee ◽  
Kyung Jin Bae ◽  
Oh Kyung Kwon
Keyword(s):  
Performance Evaluation ◽  
Physical Properties ◽  
Water Temperature ◽  
Silica Gel ◽  
System Performance ◽  
Waste Heat ◽  
Sustainable Energy ◽  
Cooling Capacity ◽  
Hot Water ◽  
Adsorption Chiller

In this study, the performance evaluation of an adsorption chiller (AD) system with three different adsorbents—silica-gel, aluminum fumarate, and FAM-Z01—was conducted to investigate the effects of adsorption isotherms and physical properties on the system’s performance. In addition, the performance evaluation of the AD system for a low inlet hot-water temperature of 60 °C was performed to estimate the performance of the system when operated by low quality waste heat or sustainable energy sources. For the simulation work, a two-bed type AD system is considered, and silica-gel, metal organic frameworks (MOFs), and ferro-aluminophosphate (FAPO, FAM-Z01) were employed as adsorbents. The simulation results were well matched with the laboratory-scale experimental results and the maximum coefficient of performance (COP) difference was 7%. The cooling capacity and COP of the AD system were investigated at different operating conditions to discuss the influences of the adsorbents on the system performance. Through this study, the excellence of the adsorbent, which has an S-shaped isotherm graph, was presented. In addition, the influences of the physical properties of the adsorbent were also discussed with reference to the system performance. Among the three different adsorbents employed in the AD system, the FAM-Z01 shows the best performance at inlet hot water temperature of 60 °C, which can be obtained from waste heat or sustainable energy, where the cooling capacity and COP were 5.13 kW and 0.47, respectively.

Two-Stage Non-Regenerative Silica Gel-Water Adsorption Refrigeration Cycle

2000 ◽  
Author(s):  
B. B. Saha ◽  
K. C. A. Alam ◽  
A. Akisawa ◽  
T. Kashiwagi ◽  
K. C. Ng ◽  
...  
Keyword(s):  
Heat Pump ◽  
Silica Gel ◽  
Water Adsorption ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Adsorption Refrigeration ◽  
Two Stage ◽  
Adsorption Chiller ◽  
Adsorption Heat Pump

Abstract Over the past two decades there have been considerable efforts to use adsorption (solid/vapor) for cooling and heat pump applications, but intensified efforts were initiated only since the imposition of international restrictions on the production and use of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). Closed-type, conventional adsorption refrigeration and heat pump systems have an increasing market share in Japan. In this paper, a two-stage non-regenerative, silica gel-water adsorption chiller design is outlined. Experimental measurements are performed on a prototype of a 3.5 kW rated cooling capacity adsorption heat pump in order to determine its performance under different operating temperatures (hot, cooling and chilled water). The chiller performance is analyzed in terms of cooling capacity and coefficient of performance (COP). The main innovative feature in the two-stage adsorption chiller is the ability to utilize low-temperature waste heat (∼55°C) as the driving source with a cooling source of 30°C. The technological difficulty inherent in operating a thermally activated cycle with such a small regenerating temperature lift (temperature difference between heat source and heat sink inlets) is overcome by use of a two-stage cycle.

scholarly journals Performance Testing and Analysis of Silica Gel-Water Adsorption Refrigerator

2022 ◽  
Vol 2160 (1) ◽  
pp. 012032
Author(s):  
Hongxuan Li ◽  
Tonghua Zou ◽  
Qingling Hui ◽  
Ting Li ◽  
Walter Mittelbach
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Water Temperature ◽  
Silica Gel ◽  
Water Adsorption ◽  
Cooling Capacity ◽  
Hot Water ◽  
Low Grade ◽  
Adsorption Refrigeration ◽  
Refrigeration Capacity

Abstract In recent years, adsorption refrigeration technology has attracted wide attention from experts and scholars at home and abroad due to its environmental friendliness and energy saving advantages. In order to study the effectiveness of adsorption refrigeration technology to recover low-grade energy, a silica gel-water adsorption refrigeration system was proposed, which can effectively utilize low-grade energy such as industrial waste heat. The structure and composition of the system are introduced. The operation performance of the unit is tested under different working conditions by orthogonal experimental method, and the experimental results are analyzed. The effects of hot water temperature and flow, chilled water temperature and flow on the refrigeration capacity and COP value of the system are obtained. The experimental results show that under the low-temperature heat source of 55-75°C, the cooling capacity of the system can reach 5.3-12 and the COP value can reach 0.36-0.56. Under the same hot water temperature difference, the cooling capacity and COP value of the system increase rapidly under the condition of changing the hot water temperature at low temperature, indicating that increasing the heat source temperature at low temperature has a greater impact on the system performance. Through the analysis of primary and secondary effects, it is concluded that the inlet temperature of hot water is the main factor affecting the refrigeration capacity and COP value of the system.

Study of Waste Heat Driven Adsorption Cooling System Employing Doped MiL-101(Cr) and Water as Adsorbent Adsorbate Pair

2015 ◽  
Author(s):  
Anutosh Chakraborty ◽  
Syed Muztuza Ali ◽  
How Wei Benjamin Teo
Keyword(s):  
Silica Gel ◽  
Waste Heat ◽  
Cooling System ◽  
Water System ◽  
Cooling Capacity ◽  
Isotherm Models ◽  
Oh Groups ◽  
Adsorption Chiller ◽  
Adsorption Isotherm Models ◽  
Adsorption Cooling System

This article presents the dynamic behaviors of two bed adsorption chiller utilizing the composite adsorbent “immobilization of NH2, -NO2, -OH groups to MiL-101(Cr)” as adsorbent and water as adsorbate, which is based on the experimentally confirmed adsorption isotherms and kinetics data. The experimentally measured MOFs + water based isotherms and kinetics data are fitted with adsorption isotherm models and linear driving force kinetics equations. Compared with the experimental data of conventional adsorption chiller based on zeolites/silica gel-water system, we found that the newly working pair provides better cooling capacity and performances in terms of COP and adsorption bed size. From numerical simulation, it is also found that the cooling capacity can be increased up to 20 percent of the parent silica gel-water adsorption chiller and the COP can be improved up to 25% more at optimum conditions.

Using Adsorption Cooling and Thermal Solar Collection for Residential Cooling Applications in Canada

2018 ◽  
Author(s):  
Jordan McNally ◽  
Christopher Baldwin ◽  
Cynthia A. Cruickshank
Keyword(s):  
Water Temperature ◽  
Flat Plate ◽  
Flow Rate ◽  
Heating System ◽  
Cooling Capacity ◽  
Hot Water ◽  
Inlet Temperature ◽  
Solar Collectors ◽  
Adsorption Chiller ◽  
The Difference

An adsorption chiller is a type of chiller that uses heat input as the driving force for chemical compression of a refrigerant and provides cooling with low electrical consumption. An experimental setup was designed, instrumented, and constructed to meet constant inlet temperature and flow rate requirements for the commercially available adsorption chiller unit tested. Two types of tests were conducted, one with a constant hot water temperature which represents a district style heating system and another with a varying hot water temperature, representing a system using flat plate solar collectors. Numerous tests were run with constant inlet temperatures across the complete operating range of the chiller and at varying flow rates for each of the three main inputs. It was determined that variations in temperature had a much more significant impact on the performance of the chiller, compared to the variations in flow rate, which were almost negligible within tested range. Dynamic inlet temperature tests were run using the modified system which uses data from a weather file to simulate a system using flat plate solar collectors and vary the hot water inlet temperature to the system. The results showed that when the average hot water inlet temperature is lower than 60°C and higher than 75°C, the difference in performance between constant inlet temperature and dynamic inlet temperature tests was very small. However, the cooling capacity at 75°C was about 4 kWth greater than at 60°C. Majority of the test produced a thermal COP between 0.45 and 0.50. Therefore, based off the solar collector system’s capacity to maintain a suitable average hot water temperature, the cooling performance of the chiller can be deemed suitable for residential applications.

Performance of Air Conditioners With Commercial Desuperheaters: A Green Energy Project as an Undergraduate Research

2009 ◽  
Author(s):  
Emin Yilmaz ◽  
Abhijit Nagchaudhuri
Keyword(s):  
Data Acquisition ◽  
Water Temperature ◽  
Heat Pump ◽  
Waste Heat ◽  
Mechanical Systems ◽  
Green Energy ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Design Project ◽  
Heating Mode

The goal of the design project titled “Domestic Hot Water Heater Using Air Conditioner Waste Heat” was to introduce students to designing mechanical systems in the “ETME475-Mechanical Systems Design” course. Two students completed the design project in spring 2007. Some test runs were conducted with a commercial desuperheater to measure the efficiency of the unit and its effect on the Coefficient of Performance (COP) of the Heat Pump when the heat pump is operated in air conditioning (A/C) mode. Contrary to author’s expectations, results indicated that, COP values were reduced by about 22%. Measured efficiency of the desuperheater was about 18% [1]. The current project is an extension of the original project with the new National Instruments data acquisition board, a newly developed LabVIEW data acquisition program, and with a more realistic heat transfer loop. The study covers performance of the heat pump operating in A/C mode as well as in heating mode. Results indicate, depending on the water temperature in the desuperheater, heat pump COP dropped 6–17% in A/C mode and 8–38% in heating mode. Again depending on the average water temperature in the ECU, the ECU efficiencies ranged from 12% to 27% for cooling and 11% to 39% for heating.

Performance Analysis of a Silica Gel-Water Adsorption Cooler: Impact of Nanofluids on Cooler Performance and Size

2015 ◽  
Author(s):  
I. P. Koronaki ◽  
M. T. Nitsas ◽  
E. G. Papoutsis ◽  
V. D. Papaefthimiou
Keyword(s):  
Heat Transfer ◽  
Silica Gel ◽  
Cooling Capacity ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Theoretical Research ◽  
Adsorption Chiller ◽  
Heat Transfer Fluids ◽  
Thermally Driven ◽  
Sorption Heat

Thermally driven chillers also known as sorption heat pumps have drawn considerable attention in recent years. They can be divided into two main categories: absorption (liquid-vapor) and adsorption (solid-vapor) systems. Even though adsorption cycles have relatively lower coefficient of performance compared to absorption cycles, however they prevail in terms of heat source, electric consumption for moving parts, crystallization etc. In order to overcome the drawback of low COP and specific cooling capacity, nanofluids, i.e. mixtures of nanometer size particles well-dispersed in a base fluid, can be used as heat transfer fluids as recent experimental and theoretical research has proved that nanofluids can exhibit a significant increase on heat transfer. In this study a two bed, single-stage adsorption chiller which utilizes the silica gel-water pair as adsorbent-refrigerant is simulated. The cooling capacity and the COP of the chiller are calculated for various cycle times. The usage of nanofluids as heat transfer fluids in the chiller evaporator and condenser and their effect on chiller performance and size is investigated. It is proved that the presence of nanofluids at different volume concentrations will enhance the cooling capacity and the COP of the adsorption chiller and therefore will lead to smaller, in terms of size, heat exchangers.

Performance of an Absorber With Hydrophobic Membrane Contactor at Aqueous Solution-Water Vapor Interface

2010 ◽  
Vol 2 (3) ◽  
Author(s):  
Ahmed Hamza H. Ali
Keyword(s):  
Aqueous Solution ◽  
Water Vapor ◽  
Water Temperature ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Hot Water ◽  
Membrane Contactor ◽  
Water Coolant ◽  
Hydrophobic Membrane ◽  
Vapor Interface

In this study, a detailed modeling of the heat and mass transfer processes inside a plate-and-frame absorber with hydrophobic microporous membrane contactor at aqueous solution-water vapor interface as a part of a chiller model is developed. The absorber is a component of a 5 kW cooling capacity single effect lithium bromide-water absorption chiller with a hot water thermally driven generator, a water-cooled absorber, and a condenser. The model is used to investigate the performance of the absorber in case the chiller operates at different values of the inlet driving hot water and cooling water (coolant) temperatures. The results clearly indicate that for the same cooling capacity of the chiller and compared with the performance at the design point value, increasing the inlet driving hot water temperature results in an increase in the required absorber size and consequently a decrease in the absorber performance, while decreasing the cooling water (coolant) inlet temperature leads to slight decreases in the required absorber size and consequently an increase in the absorber performance. The effect is prominent and can be used to decrease the absorber size for chillers work in places where the option of lower inlet coolant temperature is available with normal driving hot water temperature.

Performance Study of Waste Heat Driven Pressurized Adsorption Chiller

2013 ◽  
Vol 315 ◽  
pp. 380-384
Author(s):  
Khairul Habib
Keyword(s):  
Heat Source ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Performance Study ◽  
Adsorption Chiller ◽  
And Performance ◽  
Low Grade Heat ◽  
Adsorption Desorption

This article presents a transient modeling and performance of a waste heat driven pressurized adsorption chiller. This innovative adsorption chiller employs pitch based activated carbon of type Maxsorb III as adsorbent and R507A as refrigerant as adsorbent-refrigerant pair. This chiller utilizes low-grade heat source to power the cycle. A parametric study has been presented where the effects of adsorption/desorption cycle time, switching time and regeneration temperature on the performance are reported in terms of cooling capacity and coefficient of performance (COP). Results indicate that the adsorption chiller is feasible even when low-temperature heat source is available.

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