Design and Experimental Investigation of a Diffusion Absorption Refrigeration System

2006 ◽  
Author(s):  
Shiming Xu ◽  
Jian Liang ◽  
Yi Jian He ◽  
Ru Xu Du
Keyword(s):  
Cooling Capacity ◽  
Input Power ◽  
Experimental Results ◽  
Working Fluid ◽  
Absorption Refrigeration ◽  
Operation Condition ◽  
Operation Conditions ◽  
System Pressure ◽  
Diffusion Absorption ◽  
Bubble Pump

This paper presents the design and experimental analysis of a compact Diffusion Absorption Air Cooler (DAAC) system, in which the Diffusion Absorption Refrigeration (DAR) technology is utilized. The system uses a bubble pump to replace the mechanical pump, uses three-component working fluid (NH3+H2O+He), and operates under the same system pressure level. Hence, it is quiet, long lasting and environmental friendly. To investigate the practicality of using the DAAC system for regional air conditioning, the thermodynamic model is derived to guide the system design first, and then a DAAC experimental prototype is built for validation. Since the bubble pump is the kernel component, a series of experiments are conducted to investigate the bubble pump performance. From the experimental results under various operation conditions, it is found that the bubble pump dominates the system performance and should be designed carefully to match the designed cooling capacity and operation condition. The experimental results also show that the DAAC can work smoothly under various ambient temperatures when the input power of bubble pump is over 200W.

A Parametric Examination of the Factors Affecting the Performance of a Diffusion Absorption Refrigeration System

2021 ◽  
pp. 1-38
Author(s):  
Noman Yousuf ◽  
Timothy Anderson ◽  
Roy Nates
Keyword(s):  
Waste Heat ◽  
Operating Conditions ◽  
Design Parameters ◽  
Working Fluid ◽  
Low Grade ◽  
Absorption Refrigeration ◽  
Factors Affecting ◽  
Thermally Driven ◽  
Mass Flowrate ◽  
Diffusion Absorption

Abstract Despite being identified nearly a century ago, the diffusion absorption refrigeration (DAR) cycle has received relatively little attention. One of the strongest attractions of the DAR cycle lies in the fact that it is thermally driven and does not require high value work. This makes it a prime candidate for harnessing low grade heat from solar collectors, or the waste heat from stationary generators, to produce cooling. However, to realize the benefits of the DAR cycle, there is a need to develop an improved understanding of how design parameters influence its performance. In this vein, this work developed a new parametric model that can be used to examine the performance of the DAR cycle for a range of operating conditions. The results showed that the cycle's performance was particularly sensitive to several factors: the rate of heat added and the temperature of the generator, the effectiveness of the gas and solution heat exchangers, the mass flowrate of the refrigerant and the type of the working fluid. It was shown that can deliver good performance at low generator temperatures if the refrigerant mass fraction in the strong solution is made as high as possible. Moreover, it was shown that a H2O-LiBr working pair could be useful for achieving cooling at low generator temperatures.

THE EFFECT OF LIQUID SUCTION HEAT EXCHANGER SUB-COOLER ON PERFORMANCE OF A FREEZER USING R404A AS WORKING FLUID

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Muhammad Nuriyadi ◽  
Sumeru Sumeru ◽  
Henry Nasution
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling Capacity ◽  
Experimental Results ◽  
Working Fluid ◽  
Liquid Line ◽  
Cabin Temperature

This study presents the effect of liquid-suction heat exchangers (LSHX) sub-cooler in a freezer. The LSHX sub-cooler is a method to increase the cooling capacity of the evaporator by lowering temperature at the condenser outlet. The decrease in temperature of the condenser outlet will cause a decrease in the quality refrigerant entering the evaporator. The lower the quality of the refrigerant entering the evaporator, the higher the cooling capacity produced by the evaporator. The LSHX sub-cooler utilizes a heat exchanger to transfer heat from the outlet of the condenser (liquid line) to the suction of the compressor. In the present study, three different LSHX sub-coolers in the freezer with cabin temperature settings of 0, -10 and -20oC were investigated. The results showed that the lowest and the highest of effectiveness of the heat exchanger were 0.28 and 0.58, respectively. The experimental results also showed that EER reduction is occurred at the cabin temperature setting of 0oC and -10oC, whereas the EER improvements were always occurred at the cabin temperature settings of -20oC.

scholarly journals Experimental investigation on the flow behaviour in a bubble pump of diffusion absorption refrigeration systems

2016 ◽  
Vol 8 ◽  
pp. 1-9 ◽  
Author(s):  
Ali Benhmidene ◽  
Khaoula Hidouri ◽  
Béchir Chaouachi ◽  
Slimane Gabsi ◽  
Mahmoud Bourouis
Keyword(s):  
Experimental Investigation ◽  
Flow Behaviour ◽  
Absorption Refrigeration ◽  
Diffusion Absorption ◽  
Bubble Pump

scholarly journals Inert Gas and Refrigerating Vapor Mass Flow Rates Ratio: A Much Promising Parameter for Diffusion-Absorption-Refrigeration Systems Performances Evaluation

2021 ◽  
Vol 8 (2) ◽  
pp. 253-258
Author(s):  
Djallel Zebbar ◽  
Souhila Zebbar ◽  
Sahraoui Kherris ◽  
Kouider Mostefa
Keyword(s):  
Mass Flow ◽  
Gas Flow ◽  
Inert Gas ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Absorption Refrigeration ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Diffusion Absorption ◽  
Vapor Mass

This paper is consecrated to the thermodynamic study and analysis of diffusion-absorption-refrigeration (DAR) plants. The mass and energy balances analysis at the evaporator has allowed to highlight a new and original parameter, which can be used to analyze DAR system performances. It is the ratio of inert gas to refrigerant vapor mass flow rates at the evaporator inlets. This coefficient, which expression has been for the first time deduced mathematically, informs about the quality of the cycle and its performance, which are deeply affected by the growth of the inert gas flow energy expended to drive the refrigerant through the evaporator. The study shows that the coefficient of performance is decreasing with the increase of the mass flow rates ratio. The latter can be also used to find the optimal operating mode for the DAR machine with a specified working fluid.

Numerical Research of a Solar Driven Bubble Pump for Diffusion Absorption Refrigeration Systems

2021 ◽  
Vol 412 ◽  
pp. 27-36
Author(s):  
Bella Gurevich ◽  
Amir Zohar
Keyword(s):  
Cooling System ◽  
Cooling Capacity ◽  
Low Grade ◽  
Vapor Compression ◽  
Absorption Refrigeration ◽  
Pump Operation ◽  
Mechanical Pump ◽  
Low Grade Heat ◽  
Absorption Cooling System ◽  
Diffusion Absorption

In conventional vapor compression and absorption refrigeration systems, a compressor or a mechanical pump, respectively circulates the refrigerant. Mechanical input, which is required by the compressor or the pump operation, contributes significantly to the noise level and lessens its reliability and portability. In contrast, diffusion absorption refrigeration (DAR) systems are heat-driven and contain no moving parts. Solar-driven diffusion absorption cooling system uses a low-grade heat to produce a cooling effect, and it's specially tuned for remote locations with high levels of solar radiation. This article studies the performance of a DAR system in Ashdod, Israel. Based on existing models in the literature and on experimental measurement of quantities such as the solar irradiance and the air temperature, the cooling capacity and the COP were simulated. Cooling capacity of the DAR system varies between 100 and 140 W, and COP between 0.09 and 0.17.

Multiple lift tube pumps boost refrigeration capacity in absorption plants

2007 ◽  
Vol 18 (4) ◽  
pp. 49-57 ◽  
Author(s):  
G. Vicatos ◽  
A. Bennett
Keyword(s):  
Flow Rate ◽  
Full Range ◽  
Cooling Capacity ◽  
Current Approach ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Significant Drop ◽  
Refrigeration Capacity ◽  
Diffusion Absorption ◽  
Bubble Pump

The technology of the diffusion absorption refriger-ator is receiving renewed attention due to its ability to use exclusively, low-grade heat to produce cool-ing or heating. Its capacity, however, has been large-ly restricted to small domestic-type units because of the flow rate limitations imposed by its single lift-tube pump. To increase its refrigeration capacity, a multiple lift-tube bubble pump can be used, in order to increase the volume flow rates of the fluids, which are directly related to the amount of refriger-ant produced. Testing on a diffusion absorption plant using a multiple lift tube bubble pump, and the effects of additional tubes on the system’s per-formance have been recorded. Although a full range of heat inputs could not be implemented, because of the limitations of the components of the unit itself, it was observed that the refrigeration cooling capacity was increased without a significant drop in Coefficient of Performance (COP). It was concluded that the multiple lift tube bubble pump has no limitation to the fluid flow rate and depends solely on the amount of heat input. This gives the freedom to design the lift tube pump according to the refrigeration demand of the unit, and not the other way round which is the current approach by the manufacturers world wide.

scholarly journals Measurement Method and Experimental Analysis of Liquid Entrainment for a Flooded Evaporator of a Water-Cooled Centrifugal Chiller Based on Energy Balance

2021 ◽  
Vol 11 (17) ◽  
pp. 8165
Author(s):  
Xinghua Huang ◽  
Yunqian Zhang ◽  
Zuqiang Li ◽  
Yaolin Lin
Keyword(s):  
Energy Balance ◽  
Uncertainty Propagation ◽  
Cooling Capacity ◽  
Input Power ◽  
Exchange Capacity ◽  
Experimental Results ◽  
Coefficient Of Performance ◽  
Efficient Operation ◽  
Liquid Entrainment ◽  
Centrifugal Chiller

Liquid entrainment in a flooded evaporator has an important impact on the performance and safety of a water-cooled centrifugal chiller. In this paper, two methods for measuring the liquid entrainment factor in the evaporator of a centrifugal chiller based on energy balance are proposed. Method 1 involves only the heat exchange capacity of the evaporator and Method 2 involves both evaporator and condenser. The applicable conditions of the methods are discussed. Experimental measurements on the flooded evaporator of a single-stage water-cooled centrifugal chiller with refrigerant R134a show that, for a system with good thermal balance, there is little difference in the entrainment factor values obtained by the two methods. Method 2 was found to have slightly higher measurement accuracy, compared to Method 1. The uncertainty propagation analysis shows that for method two, the inlet and outlet water temperatures of the evaporator and condenser, motor input power, motor efficiency, transmission power loss and compressor suction and discharge temperatures are important factors. The experimental results show that the variation of the evaporator entrainment factor with refrigerant charge amount is different for different cooling capacity. At 700 and 800 refrigeration ton (RT), the entrainment factor of the test evaporator increases with the increase of refrigerant charge and the growth rate gradually accelerates. For the chiller tested, when the entrainment factor reaches 0.89% and 1.02%, respectively, at 700 ton and 800 ton, the rapid increase of the entrainment factor leads to a significant decrease in the coefficient of performance (COP) during the charging process. Based on the analysis of the experimental results, it is recommended that the maximum entrainment factor for efficient operation of the centrifugal chiller should be controlled within 1%.

Sign in / Sign up

Export Citation Format

Share Document