scholarly journals Influence of initial bed temperature on bed performance of an adsorption refrigeration system

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2583-2595 ◽  
Author(s):  
Anirban Sur ◽  
Randip Das ◽  
Ramesh Sah

The study deals with the complete dynamic analysis (numerical and practical) of an existing adsorption refrigeration system. The adsorption refrigeration setup is available at Indian School of Mines (Dhanbad, India), Mechanical engineering department. The system operates with activated carbon (as an adsorbent) and methanol (as refrigerant).Numerical model is established base on energy equation of the heat transfer fluid (water) and transient heat and mass transfer equations of the adsorbent bed. The input temperature of heat source is 90?C, which is very low compared to other low-grade energy input refrigeration system. The thermo-physical properties of an adsorptive cooling system (using activated carbon?methanol pair) are considered in this model. In this analysis influence of initial bed temperature (T1) on the bed performances are analysed mathematically and experimentally. The simulation and practical results of this system show that the cycle time decreases with increase in initial bed temperature and the minimum cycle time is 10.74 hours (884 minutes for practical cycle) for initial bed temperature of 40?C. Maximum system COP and specific cooling capacity are 0.436 and 94.63 kJ/kg of adsorbent under a condenser and evaporator temperatures of 35?C and 5?C, respectively. This analysis will help to make a comparison between simulated and experimental results of a granular bed adsorption refrigeration system and also to meet positive cooling needs in off-grid electricity regions.

2016 ◽  
Vol 24 (02) ◽  
pp. 1630003 ◽  
Author(s):  
Anirban Sur ◽  
Randip K. Das

Researchers proved that, heat powered adsorption refrigeration technology is very effective methods for reutilization of low-grade thermal energy such as industrial waste heat, solar energy, and exhaust gases from engines. But to make it commercially competitive with the well-known vapor compression and absorption refrigeration system, the processes require high rates of heat and mass transfer characteristic between adsorbate and adsorbent as well as externally supplied heat exchanging fluid. This paper reviews various techniques that have been developed and applied to enhance the heat transfer and mass transfer in adsorber beds, and also discuss their effects of the performance on adsorption system. A comprehensive literature review has been conducted and it was concluded that this technology, although attractive, has limitations regarding its heat and mass transfer performance that seem difficult to overcome. Therefore, more researches are required to improve heat and mass transfer performance and sustainability of basic adsorption cycles.


2002 ◽  
Vol 124 (3) ◽  
pp. 283-290 ◽  
Author(s):  
T. F. Qu ◽  
W. Wang ◽  
R. Z. Wang

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.


2014 ◽  
Vol 953-954 ◽  
pp. 119-122
Author(s):  
Yan Ling Liu ◽  
Xue Zeng Shi ◽  
Yuan Yu

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.


2004 ◽  
Vol 126 (1) ◽  
pp. 671-673 ◽  
Author(s):  
Wen Wang ◽  
Tianfei Qu ◽  
Zhonghua Li ◽  
Ruzhu Wang

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.


Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3975
Author(s):  
Zhongbao Liu ◽  
Banghua Zhao ◽  
Yong Huang ◽  
Xin Qi ◽  
Fengfei Lou

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.


2014 ◽  
Vol 953-954 ◽  
pp. 57-60
Author(s):  
Xiang Bo Song ◽  
Xu Ji ◽  
Ming Li ◽  
Jie Qing Fan ◽  
Bin Luo ◽  
...  

This article conducts the research on the relationship between the solar radiation and the adsorption bed temperature, the adsorption bed pressure and the system performance, and obtains that the solar radiation indirectly influences the system refrigeration performance through influencing the adsorption bed temperature and adsorption bed pressure. And in a certain range, the bigger solar radiation is, the higher adsorption bed temperature is, the system refrigeration efficiency is higher, the maximum refrigeration efficiency is 0.122.


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