Energy and exergy analysis of a double effect librh2o and liclh2o chillers m. Operating characteristics of an absorption refrigeration system depend on the properties of refrigerant, absorbent and their mixtures. The thermodynamic properties of the solution and the refrigerant circulating through the chiller have been determined by the described cycles of the libr h. This study developed a novel calculation model using the matlab language for the thermodynamic analysis of ars. Pdf thermodynamic analysis of libr and water based vapour. Therefore, this technology is widely used in air conditioning applications. This section presents data for the thermodynamic and transport properties of refrigerants, arranged for the occasional users. Lithium bromide water properties the librh2o library provides property data for saturated liquid solutions of lithium bromide in water based on the publication by patek, j. Physical properties general physical properties for freon 407c and freon 407a are shown in table 3. The expression of patek was used to calculate the thermodynamic property of the librh 2 o solution. Hvac and refrigeration system bureau of energy efficiency 72.
Mathematical model of a lithiumbromidewater absorption. A heat and mass transfer mapping for the nh h o and libr h o. Thermodynamic evaluation of liclh2o and librh2o absorption. The enthalpy and entropy of properties are validated within deviation limits 0.
Thermodynamic properties a quantity which is either an attribute of an entire system or is a function of position which is continuous and does not vary rapidly over microscopic distances, except possibly for abrupt changes at boundaries between phases of the system. The absorption system considered uses lithium bromide as the absorber and water as the refrigerant to. The aim of this study is to present a gibbs energy model to calculate the thermodynamic properties of librh 2o aqueous solution with the concentration range from 0 to 70 libr wt%. Thermodynamic modelling of a singleeffect librh2o absorption. Complex empirical expressions for entropy of li br water solution in the temperature range of 0190 8c and salt concentration of 075%. The thermodynamic properties including specific heat capacity. Although most of the absorption refrigeration heat pump systems use librh2o solution for absorbent refrigerant pair, there exist only a limited number. The main aim of this work is to study of lithium bromide water librh 2. As for the thermodynamic properties of solvent, meng studied the water activities, osmotic coefficients and vapor pressure for libr aqueous solution in wide ranges of concentration at 373. By the application of first and second law of thermodynamics with mass and energy balance equation. This article describes thermodynamic properties of the refrigerants the ideal refrigerant. Additional physical property data may be found in other chemours publications. Thermodynamic properties of duponttm freonr 12 r12.
The refrigerant in any refrigerator or air conditioner flows continuously through the vapor compression cycle, absorbing the heat in the evaporator and releasing it in the condenser. The model was coupled to a set of equations of state allowing the reliable calculation of the thermodynamic properties of the binary mixture used. Fellow ashrae mcquay international staunton, virginia usa 1 what is a refrigerant. Vapour absorption refrigeration system by using solar energy. During this process it changes its state from a liquid to a gas, and at the evaporator exit is slightly superheated. The pressureenthalpy diagrams for freon 407c are shown in figures 1 and 2. Refrigerants and their application presented by thomas e. Performance evaluation of combined ejector librh2o. The simulator used an equation of state to predict the thermodynamic properties of the refrigerant mixtures. Dec 01, 2016 the thermodynamic model was solved using the fortran program, and the time step of the model is 120 s.
Physical properties chemical formula ccl2 f2 molecular mass 120. Among the enormous working fluid pairs refrigerant absorbent combinations available in literature 2. Librh2o absorption cycle design for whole year use in medium. Thermodynamic study of a novel solar librh2o absorption. Thermodynamic analysis is the deciding tool to predict the performance behavior of any absorption system. Solubility measurements were performed by the visual method in the temperature range of. Thermodynamic properties in the schematic diagram state 1 to 4 requires the thermodynamic properties of water and state 5 to 10 are based on libr water mixture. Waterlithium bromide vapor absorption refrigeration system. Then the program calculates the thermodynamic properties of the refrigerant and solution p,t,x,h at all the state point as shown in fig 2. Thermodynamic analysis of lithium bromidewaterlibrh2o. Compare flooded and dxdry expansiontype evaporator 04 c a single compressor using r12 as refrigerant has three evaporators of capacity 30tr, 20tr and10tr. Jun 02, 2019 a refrigerant is a substance or mixture.
For thermodynamics and fluid mechanics problems, values of entropy, specific heat energy etc must be known for various fluids and their value can easily be obtained from these tables. Here are some of the desirable properties of refrigerant explained in detail. Computationally effective formulation of the thermodynamic properties of librh2o. This paper provides an analytical approach to the study of the vapor absorption refrigeration system. Mapping of optimum operating condition for librwater. An absorption refrigeration system ars is an alternative to the conventional mechanical compression system for cold production. Psychometric properties saturated and unsaturated air, dry, wet and dew point temperature humidity, specific humidity, absolute. Validation of the model figure1effect plot for sn ratios on pressure. Since water is used as refrigerant, using these systems it is not possible to provide refrigeration at below zero temperatures.
Whenever we choose them for particular use properties of refrigerants also plays a vital role in economic and environmental friendly application. In this work, optimum operating condition maps are generated covering wide ranges of refrigeration and sink temperatures for single and doubleeffect librwater vapour absorption refrigeration cycle. Hence it is used only in applications requiring refrige c. Desirable properties and commonly used refrigerants. This information is based on values calculated using the nist refprop database mclinden, m. A concentrated solution of lithium bromide has a great affinity for water. Since water is the refrigerant, the refrigerant operating temperature in the evaporator has to be above the freezing point of water 0oc of water. Pdf thermodynamics properties table suddiyas nawaz. Technical information at22 thermodynamic properties of dupontz freon. The program then gives the thermodynamic properties of all state points, the. Simultaneously the heat released to absorb the vapor is removed by air. Thermodynamic properties of librh2o solution request pdf. Study of ammonia water vapour absorption refrigeration. Thermodynamic analyses used to find the suitability of working fluids for a specific application for specific range of temperatures 1.
The pitzer and hw model was used to correlate the measured water activities and solubilities, simulate the thermodynamic properties and predict the data in the phase equilibrium process for the absorption refrigeration systems, and the predicted data agreed well with the experimental solubilities. These optimum condition maps will be useful to choose optimum operating conditions while designing librwater cycle for desired applications. Refrigerants r407c and r407a properties, uses, storage. Pdf thermodynamic evaluation of liclh2o and librh2o. However, thermodynamic analysis needs to be performed to find the suitability of a refrigerant absorbent combination for a specific application. Experimental observation of a small capacity vapor absorption. The thermodynamic properties of most common working. Energies free fulltext thermodynamic evaluation of licl. The objective of this work is to design a lithium bromidewater librh2o absorption refrigerator with a nominal capacity of 5. To enable the use of smaller compressors and other equipment the refrigerant should have smaller vapor density. The refrigerants have a thermodynamic property charge. Thermodynamic performance of a doubleeffect absorption.
Thermodynamic analysis of singleeffect lithium bromide water. Thermodynamic analysis of libr and water based vapour absorption. Although most of the absorption refrigerationheat pump systems use librh2o solution for absorbentrefrigerant pair, there exist only a limited number of reliable. Maxwell relations, clapeyron equation, clapeyron clausius equation, mayer equation, thermodynamic potentials, residual property functions, helmoholtz and gibbs functions, tds equations, fugacity of gases, henry and raults law, gibbs phase rule, hesss law, properties of multiphase systems. Energy and exergy analysis of a double effect librh o and. Thermodynamic analysis of libr and water based vapour. Maxwell relations, clapeyron equation, clapeyronclausius equation, mayer equation, thermodynamic potentials, residual property functions, helmoholtz and gibbs functions, tds equations, fugacity of gases, thermodynamic properties of homogeneous mixtures, partial molal properties. Ravul uludag university, faculty of engineering,department of mechanical engineering, 16059 bursa, turkey absorption refrigeration systems ars is a type of environmental friendly technology with zero ozone depletion and global. An intensive search for refrigerant absorbent combinations suitable for operating at temperature levels attainable with solar energy is underway. Keywords absorption refrigeration, diesel engine, energy, exergy.
Performance of a libr water absorption chiller operating with. In a waterlithium bromide vapor absorption refrigeration system, water is used as the refrigerant while lithium bromide li br is used as the absorbent. Abstract this paper work indicates the experimental investigation and performance evaluation of a small capacity of vapor absorption cooling system. These physical properties of refrigerants help us select the proper refrigerant for the application as per our requirement.
The thermodynamic properties of water and r410a were calculated with the refprop9 software. Integration of waterlithium bromide absorption refrigeration. In the paper a new librh2o sorption system for the whole year use in medium european. Modeling of the thermodynamic properties with ann determination of the thermodynamic properties of fluid pairs used in the absorption systems is one of the most difficult problems. Exergy calculation of lithium bromidewater solution and its. Experimental observation of a small capacity vapor absorption cooling system dipayan monda l, alimran, md. Usually, a fluid, used in a heat pump and refrigeration cycle that can extract heat from another body or substance. Journal of chemical and pharmaceutical sciences issn. Pdf thermodynamic analysis of a triple effect absorption cycle. The properties of refrigerant and absorbent and their the system. Although most of the absorption refrigeration heat pump systems use librh2o solution for absorbent refrigerant pair, there exist only a limited number of reliable sets of data on the bubblepoint. Simulation of main system parameters for load analysis qe was performed by using mat lab software.
Energetic analysis of single stage lithium bromide. Refrigerants are widely used in refrigeration cycle where cooling effect below the atmospheric temperatures are needed. Thermodynamic evaluation of liclh2o and librh2o absorption refrigeration systems based on a novel model and algorithm jie ren 1, zuoqin qian 1, zhimin yao 1,2, nianzhong gan 1 and yujia zhang 1 1 school of energy and power engineering, wuhan university of technology, wuhan 430063, china. Thermodynamic analysis of vapour absorption refrigeration system using solar energy20 normally, charts of enthalpytemperaturemass fraction are available which give both liquid phase as well as vapour enthalpy of mixtures. It was found to be reliable in liclh2o and librh2o ars simulations and the parametric study was performed in detail. The specific enthalpy and entropy of the libr water mixture is calculated by using correlations from reference 15. Refrigerant leakage and detection charging of refrigerant system controls. Although most of the absorption refrigerationheat pump systems use librh2o solution for absorbent refrigerant pair, there exist only a limited number of reliable sets of data on the bubblepoint. The model evaluates the thermodynamic properties of all state points, the.
Spreadsheet calculations of thermodynamic properties. Isopiestic investigation and phase equilibrium of the high. O is used as refrigerant and a solution of lithium bromide in water is used as absorbent. Properties of the lithium bromidewater solution for exergy calculation of the librh 2o solution, the thermodynamic properties are essential. Article information, pdf download for thermodynamic modelling of a singleeffect librh. The results of this program can be used either for sizing a new refrigeration. Thermodynamic analysis of vapor absorption refrigeration. In the absorber, the lithium bromide absorbs the water refrigerant, creating a solution of water and lithium bromide. Thermodynamic properties of the streams of the double effect parallel flow. Improved thermodynamic property fields of librh 2o solution. Mech07study comparison of librh2o property and exergy.