Reconsideration of T–P–x–y data and correlations for ammonia–water mixture for pressures up to 100 bar

Exergy thermodynamics is employed to analyze a binary ammonia water mixture thermodynamic cycle that produces both power and refrigeration. The analysis includes exergy destruction for each component in the cycle as well as the first law and exergy efficiencies of the cycle. The optimum operating conditions are established by maximizing the cycle exergy efficiency for the case of a solar heat source. Performance of the cycle over a range of heat source temperatures of 320–460°K was investigated. It is found that increasing the heat source temperature does not necessarily produce higher exergy efficiency, as is the case for first law efficiency. The largest exergy destruction occurs in the absorber, while little exergy destruction takes place in the boiler.

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Thermoeconomic Analysis and Multi-Objective Optimization of a Combined Cooling and Power System Using Ammonia-Water Mixture: Case Study

Journal of Energy Engineering ◽

10.1061/(asce)ey.1943-7897.0000538 ◽

2018 ◽

Vol 144 (3) ◽

pp. 05018001 ◽

Cited By ~ 4

Author(s):

Liyan Cao ◽

Jiangfeng Wang ◽

Liangqi Chen ◽

Juwei Lou ◽

Jianyong Wang ◽

...

Keyword(s):

Power System ◽

Water Mixture ◽

Multi Objective Optimization ◽

Ammonia Water ◽

Multi Objective ◽

Combined Cooling

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A New Multidimensional Graph for the Einstein Refrigeration Cycle

Fluids Engineering ◽

10.1115/imece2006-15036 ◽

2006 ◽

Author(s):

Araceli Lara V. ◽

David Sandoval C. ◽

Juan Morales G. ◽

Raymundo Lo´pez C. ◽

Arturo Lizardi R. ◽

...

Keyword(s):

Binary Systems ◽

Graphical Representation ◽

Rankine Cycle ◽

Refrigeration Cycle ◽

Water Mixture ◽

Exergy Destruction ◽

Ammonia Water ◽

Equilibrium Data ◽

Multidimensional Representation ◽

Thermodynamic Processes

An analysis of the exergy use in an Einstein refrigeration cycle is presented. The analysis is performed through the use of a new graphical multidimensional representation of the cycle. The Einstein refrigeration cycle works with ammonia, butane and water. These compounds are present in the cycle as several ammonia-water and ammonia-butane mixtures that have different compositions. In essence, the cycle transfers ammonia from an ammonia-water mixture to an ammoniabutane mixture in a series of processes and then it transfers ammonia back again to an ammonia-water mixture in another series of processes. The ammonia transfers involve heat absorptions and heat rejections that have as an effect the transfer of heat from a low temperature reservoir to a high temperature reservoir. The aforementioned multidimensional graph was built with equilibrium data of the ammonia-water and ammonia-butane binary systems for a 4 bar pressure and a 240 K to 350 K temperature range. The graphical representation is multidimensional because it shows in one graph values of concentration, temperature, enthalpy, entropy and exergy for ammonia-water mixtures and ammonia-butane mixtures. The thermodynamic states of all the process currents present in the cycle are showed in the graph, as well as are the different thermodynamic processes of the cycle. The exergy destruction rate of each device is clearly represented. The usefulness of this graph is similar to that of the T-s graph for a Rankine cycle.

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