scholarly journals A Case Study on Solar Vapour Absorption Refrigeration System

2018 ◽  
Vol 7 (4.5) ◽  
pp. 44
Author(s):  
Shabari Girish K.V.S. ◽  
Praveen R ◽  
Dipesh Nair ◽  
Debjyoti Sahu
Keyword(s):  
Developing Countries ◽  
Large Scale ◽  
Food Preservation ◽  
Coefficient Of Performance ◽  
Prototype Model ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Absorption Refrigeration System ◽  
Vapor Absorption Refrigeration

Solar refrigeration may have applications in both developed and developing countries. Applications in developing countries such as air-conditioning, vaccine storage or large scale food preservation have been the subject of scientific research. Ammonia-water based system has good COP but generally vapor absorption refrigeration system requires high generator temperature and high circulating ratio aided by a powerful pump. Our objective was to trivialize the role of circulating ratio and simultaneously achieve higher COP. A prototype model was designed, fabricated in laboratory using scrap material and tested; performance of the unit has been analyzed. A parabolic solar trough was used as a source of heat. Various components were modeled in computer and analyzed using ANSYS. The performances and effectiveness of the unit was studied by determining refrigeration effect (RE) and   coefficient of performance (COP).  

Thermodynamic Modeling and Performance Optimization of a Solar-Assisted Vapor Absorption Refrigeration System (SAVARS)

2020 ◽  
Vol 28 (01) ◽  
pp. 2050006
Author(s):  
Boris Huirem ◽  
Pradeepta Kumar Sahoo
Keyword(s):  
Performance Optimization ◽  
Fruits And Vegetables ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Absorption Refrigeration ◽  
Performance Parameters ◽  
Refrigeration System ◽  
Vapor Absorption ◽  
Absorption Refrigeration System ◽  
Vapor Absorption Refrigeration

A thermodynamic steady-state model for a single-effect lithium bromide–water (LiBr-H2O)-based vapor absorption refrigeration system of 17.5[Formula: see text]kW capacities has been presented using the first and second laws of thermodynamics. The mass, energy and exergy balance equations in each component of the vapor absorption cycle have been fitted into a computer program to carry out the calculation using the thermo-physical properties of the working fluid. The performance parameters such as coefficient of performance (COP), exergy coefficient of performance (ECOP), total exergy destruction (TED), etc. have been evaluated considering different temperatures in generator and evaporator, different LiBr concentrations in the weak and strong LiBr-H2O solution and different solution heat exchanger effectiveness. The model evaluated the optimum performance parameters like COP, ECOP, TED, etc. of the vapor absorption system by using Design Expert-12 software for an application like on-farm cooling or transit storage of fruits and vegetables.

Estimation of Operating Parameters of a Water–LiBr Vapor Absorption Refrigeration System Through Inverse Analysis

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
T. K. Gogoi
Keyword(s):  
Objective Function ◽  
Inverse Analysis ◽  
Exergy Efficiency ◽  
Operating Parameters ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Short Period ◽  
Vapor Absorption ◽  
Absorption Refrigeration System ◽  
Vapor Absorption Refrigeration

In this paper, an inverse problem is solved for estimating parameters of a steam-driven water–lithium bromide (LiBr) vapor absorption refrigeration system (VARS) using a differential evolution (DE)-based inverse approach. Initially, a forward model simulates the steady-state performance of the VARS at various operating temperatures and evaporator cooling loads (CLs). A DE-based inverse analysis is then performed to estimate the operating parameters taking VARS coefficient of performance (COP), CL, total irreversibility, and exergy efficiency as objective functions (one objective function at a time). DE-based inverse technique estimates the parameters within a very short period of elapsed time. Over 50 and 100 numbers of generations are sufficient for retrieval of COP and exergy efficiency, respectively, while it requires 150 generations for total irreversibility and CL. The study reveals that multiple combinations of parameters within a given range satisfy a particular objective function which serves as design guidelines in selecting appropriate operating parameters.

Waste-Heat Driven Miniature Absorption Refrigeration System Using Ionic-Liquid as a Working Fluid

2011 ◽  
Author(s):  
Yoon Jo Kim ◽  
Sarah Kim ◽  
Yogendra K. Joshi ◽  
Andrei G. Fedorov ◽  
Paul A. Kohl
Keyword(s):  
Ionic Liquid ◽  
Waste Heat ◽  
Coefficient Of Performance ◽  
System Level ◽  
Working Fluid ◽  
Operating Efficiency ◽  
Outlet Temperature ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Absorption Refrigeration System

An ionic-liquid (IL) is a salt in a liquid state usually with an organic cation and inorganic anion. ILs provide an alternative to the normally toxic working fluids in absorption systems, such as the ammonia/water system. They also eliminate the problems of poor temperature match, crystallization and metal-compatibility problems of the water/LiBr system. In the present study, an IL is explored the working fluid of a miniature absorption refrigeration system so as to utilize waste-heat within the system for low-cost, high-power electronics cooling. To determine performance benchmarks for the refrigerant/IL (e.g. [bmim][PF6]) pairs, system-level simulations have been carried out. An NRTL model was built and used to predict the solubility of the mixture as well as the mixture properties such as enthalpy and entropy. The properties of the refrigerants were determined using REFPROP 6.0. Saturation temperatures at the evaporator and condenser were 25°C and 50°C, respectively. Chip power was fixed at 100 W with the operating temperature set at 85°C. R32 gave the highest operating efficiency with the maximum coefficient of performance (COP) of ca. 0.55 while R134a and R152a showed comparable performance with the maximum COP of ca. 0.4 at the desorber outlet temperature of 80°C. When waste-heat is available for the system operation, R134a and R152a COPs were comparable or better than that of R32.

Study on LiBr-H2O Absorption Refrigeration System with Integral Storage

2014 ◽  
Vol 953-954 ◽  
pp. 752-756
Author(s):  
Qi Chao Yang
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Temperature ◽  
Coefficient Of Performance ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Operation Conditions ◽  
Storage Methods ◽  
Absorption Refrigeration System

The absorption thermal energy storage (TES) system stores the energy in the form of potential energy of solution and is a promising technology for efficient energy transformation process. The performance of the absorption refrigeration system with integral storage for cooling applications using LiBr-H2O as working pair under the condition without crystallization was analyzed on the basis of the first law of thermodynamics. Simulation was employed to determine the coefficient of performance (COP) and energy storage density (ESD) of the absorption TES system under different conditions such as the absorption temperature and storage temperature. The results show that the COP of the system is 0.7453 and ESD is 169.853 MJ/m3 under typical operation conditions in summer. A low absorption temperature yields both a higher COP and ESD. The solution heat exchanger could improve the COP of the system while has no effect on ESD. Results also showed that system has a good advantage when compared to other storage methods since it is do no need thermal insulation. The absorption TES may be considered as one of the promising thermal energy storage methods.

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