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.

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.

Influence of Outside Temperature on the Operation of the Adsorption Chiller

2017 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Rafał Laskowski ◽  
Adam Ruciński
Keyword(s):  
Waste Heat ◽  
Experimental Studies ◽  
Coefficient Of Performance ◽  
External Parameter ◽  
Adsorption Refrigeration ◽  
Adsorption Chiller ◽  
Type Device ◽  
Lower Temperature

Adsorption refrigeration systems are characterized by a lower coefficient of performance than the compressor type device or even absorption, but can utilize waste heat at lower temperature. The aim of the study was to determine which external parameter has the greatest impact on the efficiency of the adsorption device. As a result of experimental studies there was found that this is not the temperature of the feed but particularly the temperature of external air. For this reason, it is recommended that the adsorption device should cooperate with evaporative spray coolers, instead of with popular dry coolers. This solution will increase annual efficiency of adsorption unit approx. by 25% and significantly reduce the costs of cold generation.

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.

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.

scholarly journals An adaptive neuro-fuzzy model of a re-heat two-stage adsorption chiller

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1053-1063 ◽  
Author(s):  
Jaroslaw Krzywanski ◽  
Karolina Grabowska ◽  
Marcin Sosnowski ◽  
Anna Zylka ◽  
Karol Sztekler ◽  
...  
Keyword(s):  
Waste Heat ◽  
Thermal Conductance ◽  
Fuzzy Model ◽  
Cooling Capacity ◽  
Primary Energy ◽  
Design Parameters ◽  
Operational Parameters ◽  
Two Stage ◽  
Adsorption Chiller ◽  
Wide Range

Since the adsorption chillers do not use primary energy as driving source the possibility to employ low temperature waste heat sources in cooling energy production receives nowadays much attention of the industry and science community. However, the performance of the thermally driven adsorption systems is lower than that of other heat driven heating/cooling systems. Low coefficients of performance are one of the main disadvantages of adsorption coolers. It is the result of a poor heat transfer coefficient between the bed and the immersed heating surfaces of a built-in heat exchanger system. The purpose of this work is to study the effect of thermal conductance values of sorption elements and evaporator as well as other design parameters on the performance of a re-heat two-stage adsorption chiller. One of the main energy efficiency factors in cooling production, i. e. cooling capacity for wide-range of both design and operating parameters is analyzed in the paper. Moreover, the work introduces artificial intelligence approach for the optimization study of the adsorption cooler. The ANFIS was employed in the work. The increase in both the bed and evaporator conductance provides better performance of the considered innovative adsorption chiller. The highest obtained value of cooling capacity is 21.7 kW and it can be achieved for the following design and operational parameters of the considered re-heat two-stage adsorption chiller: Msorb = 40 kg, t = 1300 s, T = 80?C, Csorb/Cmet = 50, hAsorb = 4000 W/K, hAevap = 4000 W/K.

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.

Optimal Design of a Fin-type Silica Gel Tube Module in the Silica Gel/Water Adsorption Heat Pump

2004 ◽  
Vol 37 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Jianfang Li ◽  
Mitsuhiro Kubota ◽  
Fujio Watanabe ◽  
Noriyuki Kobayashi ◽  
Masanobu Hasatani
Keyword(s):  
Optimal Design ◽  
Heat Pump ◽  
Silica Gel ◽  
Water Adsorption ◽  
Adsorption Heat ◽  
Adsorption Heat Pump

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.

Sign in / Sign up

Export Citation Format

Share Document