scholarly journals Performance Analysis of an Adsorption Refrigeration System Working on Activated Carbon/Methanol Pair Using Finned Tube Type Adsorber Bed

2021 ◽  
Vol 39 (4) ◽  
pp. 1335-1342
Author(s):  
Palash Soni ◽  
Sruthi Lolalis ◽  
Bidyut Mazumdar ◽  
Shubhankar Bhowmick ◽  
Vivek Kumar Gaba
Keyword(s):  
Activated Carbon ◽  
Finned Tube ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Adsorption Refrigeration ◽  
Evaporator Temperature ◽  
Tube Type ◽  
Finite Difference Discretization ◽  
The Mathematical Model ◽  
Difference Discretization

Adsorption refrigeration, being a unique and eco-friendly technology, has gained popularity over conventional refrigeration systems. The present study is aimed at developing an annular finned tube adsorber model which serves as a thermal compressor in adsorption refrigeration systems. The mathematical model is addressed numerically using finite difference discretization method and explicit scheme was used for the solution. The generalized model has been simulated for activated carbon–methanol working pair. The system has an optimum cycle time of 1800s. It was found to have a highest refrigeration capacity of 260.66 kJ/kg at a regeneration temperature of 393 K and evaporator temperature of 283 K. The highest COP (Coefficient of Performance) achieved by the system is 0.3706 at a regeneration temperature of 353 K and evaporator temperature of 283 K. A highest SCP (Specific Cooling Power) of 144.8 W/kg was obtained at an evaporator temperature of 283 K and regeneration temperature of 393 K.

Modeling of a Refrigerator in Disaster Vehicle, Using Solar Energy and Engine Exhaust Gases Heat

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Shahram Derakhshan ◽  
Alireza Yazdani
Keyword(s):  
Solar Energy ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Refrigeration Cycle ◽  
Adsorption Refrigeration ◽  
Engine Exhaust ◽  
Exhaust Gases ◽  
Exhaust Heat ◽  
Heat Adsorption

In critical situations such as floods and earthquakes, the relief forces require a refrigeration for pharmaceuticals and vaccines, which could operate without an electrical energy and the alternative energies, such as solar energy, engine exhaust gases heat, and wind energy. In this paper, a refrigeration cycle has been modeled as an adsorption refrigeration cycle with an activated carbon/methanol as adsorbent/adsorbate pair and two sources of energy—solar energy and engine exhaust gases heat. The solar cycle had a collector with area of 1 m2 and the exhaust gas cycle included a heat exchanger with 100 °C temperature difference between inlet and outlet gases. The temperature profile in adsorbent bed, evaporator, and condenser was obtained from modeling. Moreover, the pressure profile, overall heat transfer coefficient of collector and adsorbent bed, concentration, and the solar radiation were reported. Results represented the coefficient of performance (COP) of 0.55, 0.2, and 0.56 for complete system, solar adsorption refrigeration, and exhaust heat adsorption refrigeration, respectively. In addition, exhaust heat adsorption refrigeration has a value of 2.48 of specific cooling power (SCP). These results bring out a good performance of the proposed model in the climate of Iran.

Study of the Effects of Mass and Heat Recovery on the Performances of Activated Carbon/Ammonia Adsorption Refrigeration Cycles

2002 ◽  
Vol 124 (3) ◽  
pp. 283-290 ◽  
Author(s):  
T. F. Qu ◽  
W. Wang ◽  
R. Z. Wang
Keyword(s):  
Activated Carbon ◽  
Working Conditions ◽  
Heat Recovery ◽  
Recovery Process ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Adsorption Refrigeration ◽  
Ammonia Adsorption ◽  
Mass Recovery

Mass recovery can play an important role to better the performance of adsorption refrigeration cycles. Cooling capacity can be significantly increased with mass recovery process. The coefficient of performance (COP) of the activated carbon/ammonia adsorption refrigeration cycle might be increased or decreased with mass recovery process due to different working conditions. The advantage is that its COP is not sensitive to the variation of heat capacity of adsorber metal and condensing and evaporating temperature. The cycle with mass and heat recovery has a relatively high COP.

Performance Investigation of Single Adsorption Refrigeration System Driven by Solar Heat Storage

2018 ◽  
Vol 26 (03) ◽  
pp. 1850025
Author(s):  
Hicham Boushaba ◽  
Abdelaziz Mimet
Keyword(s):  
System Performance ◽  
Heat Storage ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Solar Irradiation ◽  
Cooling Power ◽  
Condensation Temperature ◽  
Adsorption Refrigeration ◽  
Solar Heat

The aim of this paper is to provide a global study of an adsorption refrigeration machine driven by solar heat storage and collected by parabolic trough collector. The system operates with ammonia (as refrigerant) and activated carbon (as adsorbent). A mathematical model interpreting the progression of the heat and the mass transfer at each element of the prototype has been developed. The solar irradiation and the real ambient temperature variations corresponding to a usual summer day in Tetouan (Morocco) are considered. The system performance is evaluated trough specific cooling power (SCP) as well as solar coefficient of performance (SCOP), which was estimated by a dynamic simulation cycle. The pressure, temperature and adsorbed mass profiles in the Adsorber have been calculated. The effects of significant design and operating parameters on the system performance have been investigated. The results show the capability of our system to realize an encouraging performance and to overcome the intermittence of the adsorption refrigeration machines. For a daily solar irradiation of 18[Formula: see text]MJ[Formula: see text]m[Formula: see text] and operating conditions of evaporation temperature [Formula: see text]C, condensation temperature [Formula: see text]C and generation temperature [Formula: see text]C, the results show that the process could achieve an SCP of 115[Formula: see text]W[Formula: see text]kg[Formula: see text] and it could produce a daily specific cooling capacity of 3310[Formula: see text]kJ[Formula: see text]kg[Formula: see text], whereas its SCOP could attain 0.141.

Thermoelectric Cooler Based Regenerative Adsorption Refrigeration System for High Temperature Electronics

2007 ◽  
Author(s):  
Ashish Sinha ◽  
Yogendra Joshi ◽  
Bruce H. Storm
Keyword(s):  
Coefficient Of Performance ◽  
Thermoelectric Cooler ◽  
Adsorption Refrigeration ◽  
Evaporator Temperature ◽  
Excess Heat ◽  
High Temperature Electronics ◽  
Bed Temperature ◽  
Heat Regeneration ◽  
A Tec ◽  
Adsorption Cycle

This paper presents the analytical study of a thermoelectric cooler (TEC) based two-stage regenerative adsorption cycle with evaporator temperature ranging from 80°C to 180°C and heat rejection temperature ranging from 200°C to 230°C. This proposed cycle restricts the highest temperature at which the TEC regenerates heat by reducing the maximum bed temperature during the desorption phase, which leads to the possibility of the system being realized with commercially available TECs and a reasonable TEC coefficient of performance (COP∼ 0.4). The low COP (<1) of the TEC results in excess heat at the desorption bed during heat regeneration. If the excess heat is rejected to the environment, COP gains arising from regeneration are reduced. Using the TEC to regenerate only part of the heat helps to mitigate this problem. The adsorption cycle in conjunction with TEC can pump heat through larger temperature differences with system efficiency much greater than that of a TEC used alone under identical conditions. The study aims to extend the limits of the adsorption refrigeration systems to provide compact cooling devices for harsh environments.

Simulation and performance study of a two-bed adsorption cooling system operated with activated carbon-ethanol

2021 ◽  
pp. 095440622110420
Author(s):  
V Baiju ◽  
A Asif Sha ◽  
NK Mohammed Sajid ◽  
K Muhammedali Shafeeque
Keyword(s):  
Water Temperature ◽  
Performance Optimization ◽  
Cooling System ◽  
Cooling Water ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Performance Study ◽  
Evaporator Temperature ◽  
Adsorption Cooling System

This paper presents the transient model of a two-bed adsorption cooling system performed in the SIMULINK platform. The inlet chilled water temperature in the evaporator, temperature of cooling water and hot water temperature of the adsorbent bed and its effect on systems coefficient of performance, refrigeration effect and specific cooling power have been studied and presented. It is observed that the systems coefficient of performance is 0.57 when the inlet hot water temperature about 80 °C. In this study, the optimum cooling power and systems coefficient of performance are also determined in terms of the phase time, shifting duration and hot water inflow temperature. The results indicates that the cooling water and hot water inlet temperatures significantly affects the coefficient of performance, specific cooling power and cooling power of the system. The effect of mass flow rate on the cooler efficiency is also presented. A two bed adsorption system of capacity 13.5 kW having an evaporator and condenser temperatures of 6°C and 28°C, respectively, are considered for the present investigation. The adsorbent mass considered is 45 kg with a shifting duration of 20 sec. The result of this study gives the basis for performance optimization of a practical continuous operating vapour adsorption cooler.

scholarly journals Performance Prediction of Solar Adsorption Refrigeration System by Ann

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
V. Baiju ◽  
C. Muraleedharan
Keyword(s):  
Neural Network ◽  
Performance Prediction ◽  
Conjugate Gradient ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Performance Parameters ◽  
Refrigeration System ◽  
Back Propagation Algorithm ◽  
Adsorption Refrigeration ◽  
Discharge Temperature

This paper proposes a new approach for the performance analysis of a single-stage solar adsorption refrigeration system with activated carbon-R134a as working pair. Use of artificial neural network has been proposed to determine the performance parameters of the system, namely, coefficient of performance, specific cooling power, adsorbent bed (thermal compressor) discharge temperature, and solar cooling coefficient of performance. The ANN used in the performance prediction was made in MATLAB (version 7.8) environment using neural network tool box.In this study the temperature, pressure, and solar insolation are used in input layer. The back propagation algorithm with three different variants namely Scaled conjugate gradient, Pola-Ribiere conjugate gradient, and Levenberg-Marquardt (LM) and logistic sigmoid transfer function were used, so that the best approach could be found. After training, it was found that LM algorithm with 9 neurons is most suitable for modeling solar adsorption refrigeration system. The ANN predictions of performance parameters agree well with experimental values with R2 values close to 1 and maximum percentage of error less than 5%. The RMS and covariance values are also found to be within the acceptable limits.

scholarly journals Design Optimization and Simulation of an Ice Plant Working by Solar Adsorption Technology

2021 ◽  
Vol 1 (4) ◽  
pp. 13-22
Author(s):  
H. A. Alamoudi ◽  
A. M. Abdel-Dayem
Keyword(s):  
Activated Carbon ◽  
Design Optimization ◽  
Winter Season ◽  
Coefficient Of Performance ◽  
Ice Plant ◽  
Adsorption Refrigeration ◽  
Model And Simulation ◽  
Adsorption Technology ◽  
Optimization And Simulation ◽  
Evacuated Tube Collectors

This research presents a design optimization of a solar adsorption ice plant using activated carbon and methanol as working pairs in the climate of Makkah to produce a ton of ice per day. The plant consists of six adsorption refrigeration units. Each unit has 72 separate cylindrical adsorbent beds connected with its own condenser, valve, and evaporator. The unit is heated by seven evacuated-tube collectors connected in parallel. Then the total number of collectors are 42 collectors. The beds are filled by estimated amount of 540 kg of activated carbon with 178 kg of methanol. Selection and dimensioning of each component were carried out based on previous recommended values. A mathematical model and simulation were developed to validate the system performance along the year. The results showed that plant could produce up to ton of ice daily along the year. The coefficient of performance can reach 0.9 with condenser and evaporator temperatures of 35°C and -5°C respectively. The performance of the system is greatly affected by ambient temperature than solar radiation. Therefore, the best performance and largest amount of ice was found in the winter season.

scholarly journals Experimental and Theoretical Study of the Energy Flow of a Two Stages Four Generators Adsorption Chiller

2019 ◽  
Vol 14 (2) ◽  
pp. 129-136
Author(s):  
Faeza Mahdi Hadi
Keyword(s):  
Activated Carbon ◽  
Cold Water ◽  
Water Cycle ◽  
Electrical Power ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Low Grade ◽  
Adsorption Chiller ◽  
Two Stages

This work is concerned with a two stages four beds adsorption chiller utilizing activated carbon-methanol adsorption pair that operates on six separated processes. The four beds that act as thermal compressors are powered by a low grade thermal energy in the form of hot water at a temperature range of 65 to 83 °C.  As well as, the water pumps and control cycle consume insignificant electrical power. This adsorption chiller consists of three water cycles. The first water cycle is the driven hot water cycle. The second cycle is the cold water cycle to cool the carbon, which adsorbs the methanol. Finally, the chilled water cycle that is used to overcome the building load. The theoretical results showed that average cycle cooling power is 2.15kW, while the experimental measurement revealed that the cooling capacity of the cycle is about 1.98 kW with a relative error of % 0.02. The generator and condensing temperatures are 83 and 30 °C, respectively. The coefficient of performance (COP) of that chiller was in the range of 0.37 to 0.49. The best operating point and the best working conditions were also investigated. The present chiller is superior more than the single stage, two beds adsorption chiller that works on the activated carbon methanol pair that needs a high ambient temperature.

scholarly journals Improving the Energy Efficiency of Adsorption Chillers by Intensifying Thermal Management Systems in Sorbent Beds

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Brian K. Paul ◽  
Kijoon Lee ◽  
Hailei Wang
Keyword(s):  
Thermal Management ◽  
Heat Exchangers ◽  
System Performance ◽  
Thermal Model ◽  
Coefficient Of Performance ◽  
Management Systems ◽  
Cooling Power ◽  
Thermal Mass ◽  
Adsorption Refrigeration ◽  
Microchannel Heat Exchanger

The objective of this study was to develop a strategy for miniaturizing heat exchangers (HXs) used for the thermal management of sorbent beds within adsorption refrigeration systems. The thermal mass of the microchannel heat exchanger (MCHX) designed and fabricated in this study is compared with that of commercially available tube-and-fin HXs. Efforts are made to quantify the overall effects of miniaturization on system coefficient of performance (COP) and specific cooling power (SCP). A thermal model for predicting the cycle time for desorption is developed, and experiments are used to quantify the effect of the intensified HX on overall system performance.

Improving the Energy Efficiency of Adsorption Chillers by Intensifying Thermal Management Systems in Sorbent Beds

2017 ◽  
Author(s):  
Brian K. Paul ◽  
Kijoon Lee ◽  
Hailei Wang
Keyword(s):  
Heat Exchanger ◽  
Thermal Management ◽  
Heat Exchangers ◽  
Thermal Model ◽  
Coefficient Of Performance ◽  
Management Systems ◽  
Cooling Power ◽  
Thermal Mass ◽  
Adsorption Refrigeration ◽  
Microchannel Heat Exchanger

The objective of this study was to develop a strategy for miniaturizing heat exchangers used for the thermal management of sorbent beds within adsorption refrigeration systems. The thermal mass of the microchannel heat exchanger designed and fabricated in this study is compared with that of commercially available tube-and-fin heat exchangers. Efforts are made to quantify the overall effects of miniaturization on system coefficient of performance and specific cooling power. A thermal model for predicting the cycle time for desorption is developed and experiments are used to quantify the effect of the intensified heat exchanger on overall system performance.

Sign in / Sign up

Export Citation Format

Share Document