Comparison of an Adsorption Refrigeration Unit Operating with Two and Four Adsorbers

2017 ◽  
Author(s):  
Andrzej Grzebielec
Keyword(s):  
Cooling Capacity ◽  
Adsorption Refrigeration ◽  
Entire Process ◽  
Refrigeration Unit ◽  
Operating Unit ◽  
Over Time

Adsorption refrigeration systems can be built with one, two or more adsorbers. The most common devices are built of two adsorbers. This fact makes the achieved cooling capacity is variable over time, and in some periods of operation is even 0 kW. Increased number of adsorbers causes the cooling capacity obtained in time is more balanced. The aim of the study is to compare the most popular operating unit with two adsorbers with the installation which continuously work with four adsorbers. It turns out that such a solution can align cooling capacity during the entire process. This solution does not affect the effectiveness of the device, but only on its size. Absorbers are the largest part of the device. So this type of solution is dedicated to wherever it is needed fluently providing cooling capacity and there is no possibility of collecting cooling in tanks.

scholarly journals Calculation algorithm for operating parameters of steam-compressive chilling machine with adsorptive chillling unit

2020 ◽  
Vol 8 (2) ◽  
pp. 3-9
Author(s):  
E.A. Belyanovskaya ◽  
◽  
G.M. Pustovoy ◽  
A.I. Sklyarenko ◽  
M.P. Sukhyy ◽  
...  
Keyword(s):  
Silica Gel ◽  
Thermal Energy ◽  
Sodium Acetate ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Coefficient Of Performance ◽  
Adsorptive Capacity ◽  
Operating Parameters ◽  
Adsorption Refrigeration ◽  
Refrigeration Unit

The work is focused on the development of an effective algorithm for calculating the operational characteristics of a steamcompressive chilling machine with an adsorptive chilling unit, which involves a cold box, an adsorber, an evaporator and a condenser, water being used as a refrigerant. An algorithm for calculating the operating parameters of the adsorptive chilling unit has been developed, which includes the determination of the cooling capacity of the steam compressor refrigeration unit, the heat load on the condenser, the power consumed by the compressor, the coefficient of performance of the steam compressor refrigeration unit, as well as the calculation of the mass of water, the mass of the adsorbent, the refrigerating capacity, the coefficient of performance of the adsorptive chilling unit and the coefficient of useful energy utilization of a steam compressive chilling machine with an adsorption chilling unit. The chilling capacity and the coefficient of performance of the adsorption chilling unit are estimated under the operating conditions of a typical steam compression chilling machine. The crucial factors affecting the efficiency of the adsorptive chilling unit are analyzed. It has been established that the chilling capacity, the coefficient of performance of the adsorption refrigeration module and the energy efficiency of the installation are determined by the thermal load on the condenser, and, therefore, by the mass of water that is desorbed and evaporated. The coefficient of performance of the adsorption chilling unit and the efficiency of the steam compressor chilling machine with the adsorptive chilling unit are estimated to be 0.878 and 4.64. The criteria for the selection of adsorbents for the adsorption module are analyzed. The temperature of regeneration is determined by the temperatures in the condenser, and the limit adsorption affects the mass of the adsorbent and the size of the adsorber. A comparison of the efficiency of adsorptive chi l l ing uni t based on silicoaluminophosphates and composite adsorbents «silica gel – sodium acetate» is carried out. The prospects of using composites «silica gel – СН3СООNa» are shown. The optimal composition of the composite was established, which corresponds to the minimal size of the adsorber, (80% sodium acetate and 20% silica gel). The prospects of using adsorptive conversion of thermal energy for utilization of low-potential thermal energy during the operation of steam compressive chilling machine are shown. Keywords: adsorptive conversion of heat energy, composite adsorbent, steam compressive chilling unit, adsorption, adsorptive capacity.

Energy Recovery Methods in Adsorption Refrigeration Units

2017 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Adam Szelągowski ◽  
Adam Ruciński
Keyword(s):  
Energy Loss ◽  
Thermal Wave ◽  
Energy Recovery ◽  
Type Systems ◽  
Adsorption Refrigeration ◽  
Wave Type ◽  
Recovery Processes ◽  
Refrigeration Unit ◽  
The One ◽  
Heat And Mass Recovery

Adsorption refrigeration systems, as opposed to absorption type operate in a cyclic manner. The result is that at the beginning of each process must be fed into the adsorber state in which they will adsorb or desorb a refrigerant. In the case of two adsorbers at the start of a cycle, the one of the adsorber must be refrigerated while the second has to be heated. These processes are causing unnecessary energy loss. The aim of the work is to show how these processes can be connected and the heat received from one adsorber is transported to another adsorber. As part of the study, the heat and mass recovery processes will be considered. It turns out that in the thermal wave type systems, it is possible to recover more than 25% of the energy lost to bring the adsorber to the states in which they will operate efficiently to desorb and adsorb refrigerant. That is, it is possible to improve the efficiency of the adsorption refrigeration unit using the proposed improvements.

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.

Mathematical Analysis on a Special Adsorption Refrigeration System Suitable for Solar Energy System

2014 ◽  
Vol 953-954 ◽  
pp. 119-122
Author(s):  
Yan Ling Liu ◽  
Xue Zeng Shi ◽  
Yuan Yu
Keyword(s):  
System Performance ◽  
Energy System ◽  
Cooling Capacity ◽  
Refrigeration System ◽  
Adsorption Refrigeration ◽  
Study Results ◽  
Actual Use ◽  
Working Principle ◽  
Set Up ◽  
New System

s. In this paper, a new adsorption refrigeration system is designed and calculated. In this system, there are two beds, two condensers and two evaporators. The working principle is explained and specified in this paper. And mathematical models are also set up and through calculation, the system performance is analyzed and evaluated.Theory study results demonstrate that the new system nearly has the same cooling capacity as conventional system and this kind of system can be adopted in actual use.

scholarly journals Experimental Study of a Solar Adsorption Refrigeration Unit, Factorial Analysis

2012 ◽  
Vol 03 (02) ◽  
pp. 126-132 ◽  
Author(s):  
Ghassan M. Tashtoush ◽  
Bourhan M. Tashtoush ◽  
Mustafa M. Jaradat
Keyword(s):  
Experimental Study ◽  
Factorial Analysis ◽  
Adsorption Refrigeration ◽  
Refrigeration Unit

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.

A Combined Cycle of Heating and Adsorption Refrigeration: Theory and Experiment

2001 ◽  
Vol 124 (1) ◽  
pp. 70-76 ◽  
Author(s):  
R. Z. Wang ◽  
M. Li ◽  
Y. X. Xu ◽  
J. Y. Wu ◽  
H. B. Shou
Keyword(s):  
Electric Heating ◽  
Cooling Capacity ◽  
Combined Cycle ◽  
Water Heater ◽  
Adsorption Refrigeration ◽  
Theoretical Simulation ◽  
Heating And Cooling ◽  
Household Water ◽  
Solar Powered ◽  
Good Agreement

A combined cycle capable of heating and adsorption refrigeration is proposed, and the experimental prototype has been installed. The system consists of a heater, a water bath, an activated carbon-methanol adsorption bed and an ice box. This system has been tested with electric heating, and has been found that with 61 MJ heating, the 120 kg water in the bath can be heated from 22°C to 92°C, of while 9 kg ice at −1.5°C is made. The calculated COPsystem is 0.0591 and COPcycle is 0.41. After reconstruction to a real hybrid household water heater-refrigerator, when 55 MJ heating is added to 120 kg of 21°C water, and the condensing temperature is controlled at about 30°C, the result is the 4 kg water contained inside the methanol refrigerant evaporator was iced to −2°C, the cooling capacity of the ice and the refrigerant in the evaporator will maintain the 100 liter cold box for about three days below 5°C. The experiments show the potential of the application of the solar powered hybrid water heater and refrigerator. Theoretical simulation has been done, which is in good agreement with experimental results. This research shows that the hybrid solar water heating and ice-making is reasonable, and the combined cycle of heating and cooling is meaningful for real applications of adsorption systems.

scholarly journals Possibility of using adsorption refrigeration unit in district heating network

2015 ◽  
Vol 36 (3) ◽  
pp. 15-24 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Artur Rusowicz ◽  
Maciej Jaworski ◽  
Rafał Laskowski
Keyword(s):  
Air Conditioning ◽  
District Heating ◽  
Hot Water ◽  
Transitional Period ◽  
Heat Sources ◽  
Adsorption Refrigeration ◽  
Refrigeration Equipment ◽  
A Value ◽  
Refrigeration Unit ◽  
Conditioning Equipment

Abstract Adsorption refrigeration systems are able to work with heat sources of temperature starting with 50 °C. The aim of the article is to determine whether in terms of technical and economic issues adsorption refrigeration equipment can work as elements that produce cold using hot water from the district heating network. For this purpose, examined was the work of the adsorption air conditioning equipment cooperating with drycooler, and the opportunities offered by the district heating network in Warsaw during the summer. It turns out that the efficiency of the adsorption device from the economic perspective is not sufficient for production of cold even during the transitional period. The main problem is not the low temperature of the water supply, but the large difference between the coefficients of performance, COPs, of adsorption device and a traditional compressor air conditioning unit. When outside air temperature is 25 °C, the COP of the compressor type reaches a value of 4.49, whereas that of the adsorption device in the same conditions is 0.14. The ratio of the COPs is 32. At the same time ratio between the price of 1 kWh of electric power and 1 kWh of heat is only 2.85. Adsorption refrigeration equipment to be able to compete with compressor devices, should feature COPads efficiency to be greater than 1.52. At such a low driving temperature and even changing the drycooler into the evaporative cooler it is not currently possible to achieve.

Application of Suction Line Heat Exchanger on Adsorption Refrigeration System

2004 ◽  
Vol 126 (1) ◽  
pp. 671-673 ◽  
Author(s):  
Wen Wang ◽  
Tianfei Qu ◽  
Zhonghua Li ◽  
Ruzhu Wang
Keyword(s):  
Experimental Data ◽  
Heat Exchanger ◽  
Cooling Capacity ◽  
Cycle Performance ◽  
Refrigeration Cycle ◽  
Refrigeration System ◽  
Adsorption Refrigeration ◽  
Suction Line ◽  
Suction Line Heat Exchanger ◽  
Condensed Liquid

Quantitative thermodynamic analysis demonstrates that an adsorption refrigeration cycle could get higher cycle performance by employing a suction line heat exchanger (SLHX). Low temperature evaporated gas not only helps to cool down the adsorbent, it further increases the cooling output by recovering heat and cooling the condensed liquid. Experimental data also verifies that a SLHX recovers heat from the evaporated gas and helps the evaporator to provide higher cooling capacity.

scholarly journals Cooling Capacity Test for MIL-101(Cr)/CaCl2 for Adsorption Refrigeration System

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3975
Author(s):  
Zhongbao Liu ◽  
Banghua Zhao ◽  
Yong Huang ◽  
Xin Qi ◽  
Fengfei Lou
Keyword(s):  
Water Vapor ◽  
Cooling Capacity ◽  
Water Vapor Adsorption ◽  
Condensation Temperature ◽  
Refrigeration System ◽  
Adsorption Refrigeration ◽  
Vapor Adsorption ◽  
Evaporation Temperature ◽  
Adsorption Temperature ◽  
Adsorption Desorption

An MIL-101(Cr) powder material was successfully prepared using the hydrothermal synthesis method, and then the original MIL-101(Cr) was combined with different mass fractions of CaCl2 using the immersion method to obtain a MIL-101(Cr)/CaCl2 composite material. The physical properties of the adsorbent were determined by X-ray powder diffraction (XRD), an N2 adsorption desorption isotherm test, and thermogravimetric analysis (TG). The water vapor adsorption performance of the metal-organic frameworks MOFs was tested with a gravimetric water vapor adsorption instrument to analyze its water vapor adsorption mechanism. Based on the SIMULINK platform in the MATLAB software, a simulation model of the coefficient of performance (COP) and cooling capacity of the adsorption refrigeration system was established, and the variation trends of the COP and cooling capacity of the adsorption refrigeration system under different evaporation/condensation/adsorption/desorption temperatures was theoretically studied. MIL101-(Cr)/CaCl2-20% was selected as the adsorption material in the adsorption refrigeration system through the physical characterization of composite materials with different CaCl2 concentrations by means of adsorption water vapor test experiments. A closed adsorption system performance test device was built based on the liquid level method. The cooling power per unit and adsorbent mass (COP and SCP) of the system were tested at different evaporation temperatures (288 K/293 K/298 K); the adsorption temperature was 298 K, the condensation temperature was 308 K, and the desorption temperature was 353 K. The experimental results showed that COP and SCP increased with the increase in the evaporation temperature. When the evaporation temperature was 298 K, the level of COP was 0.172, and the level of SCP was 136.9 W/kg. The COP and SCP of the system were tested at different adsorption temperatures (293 K/298 K/303 K); the evaporation temperature was 288 K, the condensation temperature was 308 K, and the desorption temperature was 353 K. The experimental results showed that the levels of COP and SCP decreased with the increase in the adsorption temperature. When the adsorption temperature was 293 K, the level of COP was 0.18, and the level of SCP was 142.4 W/kg.

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