Dynamic Modeling and Simulation for Double Effect Absorption Refrigeration Using [mmim]DMP/CH3OH as Working Pairs

The dynamic modeling and simulation based on components for parallel type and series type absorption refrigeration using novel working pairs [mmim]DMP/CH3OH were conducted. The modified UNIFAC model and Wilson model were used to describe the vapor liquid equilibrium and excess enthalpy of the [mmim]DMP/CH3OH solution, respectively. Under certain assumptions, the dynamic model was developed including the HPG (high pressure generator) model, the LPG (low pressure generator)-condenser model, the absorber-evaporator model and the SHX (solution heat exchanger) model. The effect of exhaust gas inlet temperature and chilled water inlet temperature on the thermodynamic performances were presented and discussed. The best COP of 1.27 and 1.17 for parallel type and series type system, respectively, were observed. The transient responses at step changes of two variables and on experimental conditions were carried out and analyzed, and the latter had been compared with the experimental data in literature. It is indicated that the model well describes the stable and transient characteristics of the double effect absorption refrigeration using [mmim]DMP/CH3OH, and can be employed to enable the further parameter optimization and control design.

Download Full-text

Design of a Solar Assisted Absorption Refrigeration System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.953-954.66 ◽

2014 ◽

Vol 953-954 ◽

pp. 66-73

Author(s):

Yan Ling Liu ◽

Xue Zeng Shi ◽

Yuan Yu

Keyword(s):

High Pressure ◽

Solar Energy ◽

System Simulation ◽

Double Effect ◽

Absorption Refrigeration ◽

Refrigeration System ◽

Absorption System ◽

Pressure Generator ◽

Simulation Results ◽

Absorption Refrigeration System

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.

Download Full-text

Dynamic modeling and simulation of a double-effect absorption heat pump

International Journal of Refrigeration ◽

10.1016/j.ijrefrig.2016.07.018 ◽

2016 ◽

Vol 72 ◽

pp. 171-191 ◽

Cited By ~ 10

Author(s):

Alberto de la Calle ◽

Lidia Roca ◽

Javier Bonilla ◽

Patricia Palenzuela

Keyword(s):

Modeling And Simulation ◽

Heat Pump ◽

Dynamic Modeling ◽

Double Effect ◽

Absorption Heat Pump

Download Full-text

Advanced Exergetic Analysis of a Double-Effect Series Flow Absorption Refrigeration System

Journal of Energy Resources Technology ◽

10.1115/1.4047082 ◽

2020 ◽

Vol 142 (10) ◽

Cited By ~ 1

Author(s):

Dario Colorado-Garrido

Keyword(s):

Second Law Of Thermodynamics ◽

Double Effect ◽

Exergy Destruction ◽

Absorption Refrigeration ◽

Pressure Generator ◽

Exergetic Analysis ◽

Absorption Refrigeration System ◽

Design And Manufacture ◽

Account Temperature ◽

Theoretical Results

Abstract This paper contains theoretical results of an advanced exergy study of a double-effect series flow absorption refrigeration cycle. Traditional second law of thermodynamics analysis was performed and revealed the absorber as the component with the highest exergy destruction of the system. In the evaporator, ≈49.34% of the exergy destruction is avoidable and almost in it’s entirety, ≈99.12% is of endogenous nature. The highest potential for improvement of the high-pressure generator is its design and manufacture because ≈67.47% of the endogenous exergy destruction is avoidable. A parametric study was presented to discuss the sensitivity of splitting exergy destruction concepts taking into account temperature variations in the absorber and condenser temperatures and the heat source temperature.

Download Full-text

Dynamic Modeling and Simulation of Saturators for Humid Air Turbine Cycle

Volume 7: Turbo Expo 2004 ◽

10.1115/gt2004-53415 ◽

2004 ◽

Author(s):

Yongwen Liu ◽

Ming Su

Keyword(s):

Modeling And Simulation ◽

Water Flow ◽

Dynamic Modeling ◽

Gas Flow ◽

Simulation Software ◽

Inlet Temperature ◽

Humid Air ◽

Spray Tower ◽

Air Turbine ◽

Number Of Segments

This paper describes the dynamic modeling and simulation of spray tower saturator using one-dimensional flow control volume method, as a part of study for dynamic modeling of the humid air turbine cycle. The mass, energy and momentum exchanges between gas flow and water flow, as well as their conservations, are taken into consideration. Separate modules are built for gas flow and water flow, and are put into an application library of EASY5, which is general-purpose simulation software. Modular structure and mathematical causality needed by explicit modeling are maintained for the modules in the application library. Then spray tower saturators can be divided into arbitrary number of segments, and each one is modeled by a gas flow module and a water flow module. To exemplify the modeling method, two dynamic models with different number of segments are built for a spray tower saturator. For steady state analysis, quantity variations with tower height at design point are illustrated, and the results of the two models are compared. For dynamic analysis, two dynamic simulations are run to obtain response to 10% step increase of the gas and water inlet temperature respectively. Estimation of the dominant time constants by linearized model is also discussed.

Download Full-text

Investigating the effect of using nanofluids on the performance of a double-effect absorption refrigeration cycle combined with a solar collector

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650919889811 ◽

2019 ◽

Vol 234 (7) ◽

pp. 981-993 ◽

Cited By ~ 3

Author(s):

Mohamad Aramesh ◽

Fathollah Pourfayaz ◽

Mehdi Haghir ◽

Alibakhsh Kasaeian ◽

Mohammad H Ahmadi

Keyword(s):

Heat Transfer ◽

Ag Nanoparticles ◽

Pure Water ◽

Double Effect ◽

Heat Transfer Fluid ◽

Working Fluid ◽

Inlet Temperature ◽

Refrigeration Cycle ◽

Outlet Temperature ◽

Absorption Refrigeration

In this article, the performance of a double-effect LiBr-H2O absorption refrigeration cycle is studied and is improved by applying solar energy and utilizing nanofluids. A trough collector is used to preheat the working fluid before entering the generator of the cycle. In addition, four different nanofluids are considered as the heat transfer fluid of the collector: Al2O3, Ag, Cu, and CuO. The effects of using nanofluids on the outlet temperature of the heat transfer fluid, the temperature of the working fluid entering the generator, the heat produced by the generator, and COP of the cycle are studied. Different concentrations of the nanoparticles from 0 to 2.5% are considered for the nanofluids. The results indicate that in all the concentrations, Ag nanoparticles will have a better performance comparing to the other types. Furthermore, it was concluded that the higher concentrations of the nanoparticles and along with it the higher inlet temperature of the generator will decrease the generator heat production rate up to 4%. Moreover, considering the constant cooling capacity of the cycle, usage of the Ag nanoparticles in the concentration of 2.5% increases the value of COP up to 3.9%, with respect to the pure water.

Download Full-text