scholarly journals Simulation and Analysis of Biogas operated Double Effect GAX Absorption Refrigeration System

Author(s):  
G. Subba Rao ◽  
Vemuri Lakshminarayana

A thermodynamic simulation of a double effect generator heat exchanger absorption refrigeration cycle using biogas as source of energy has been carried out. The binary mixture considered in the present investigation was NH3 – H2O (Ammonia - Water). This simulation was performed in order to investigate the effect of the temperature and pressure of the high temperature generator and the pressure of evaporator have over the Coefficient of Performance (COP) for a constant condenser and absorber temperatures. The basic parameters at various state points of the cycle was computed using standard correlations. The solution circulation rates and volume of biogas required for operation of the cycle are analysed for the variations in operating parameters at the high temperature generator and evaporator.

2014 ◽  
Vol 953-954 ◽  
pp. 66-73
Author(s):  
Yan Ling Liu ◽  
Xue Zeng Shi ◽  
Yuan Yu

This paper presents the design of a solar/gas driving double effect LiBr-H2O absorption system. In order to use solar energy more efficiently, a new kind of solar/gas driving double effect LiBr-H2O absorption system is designed. In this system, the high-pressure generator is driven by conventional energy, natural gas, and solar energy together with water vapor generated in the high-pressure generator, which supplies energy to the low-pressure generator for a double effect absorption system. Simulation results illustrate that this kind of system is feasible and economical. Economic evaluation of several systems is also given in this paper in order to get a clear knowledge of the energy consumption of the system.


Author(s):  
Yoon Jo Kim ◽  
Sarah Kim ◽  
Yogendra K. Joshi ◽  
Andrei G. Fedorov ◽  
Paul A. Kohl

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.


Sign in / Sign up

Export Citation Format

Share Document