Thermodynamic study of advanced absorption heat transformers—I. Single and two stage configurations with heat exchangers

Rivera, W.; Best, R.; Hernández, Jesús Hernández; Heard, C.L.; Holland, F.A.

doi:10.1016/0890-4332(94)90008-6

Cited by 51 publications

(13 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mathematical pattern used for the simulation of this system is based on a thermodynamic model published previously [6]. This modeling has been tested and compared to simulated and experimental data showing a good agreement [8].…”

Section: Basic Conceptsmentioning

confidence: 99%

Increase of COP for heat transformer in water purification systems. Part II – Without increasing heat source temperature

Romero

Siqueiros

Huicochea

2007

Applied Thermal Engineering

View full text Add to dashboard Cite

The integration of a water purification system allows a heat transformer to increase the actual coefficient of performance, by the reduction of the amount of heat supplied by unit of heat. A new defined COP called COP WP is proposed for the present system, which considers the fraction of heat recycled. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP ET ) and water purification coefficient of performance (COP WP ) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that the proposed (AHTWP) system is capable of increasing the original value of COP ET up to 1.6 times its original value by recycling energy from a water purification system. The proposed COP WP allows increments for COP values from any experimental data for water purification or for any other distillation system integrated to a heat transformer, regardless of actual COP A value or working fluid-absorbent pair.

show abstract

Section: Basic Conceptsmentioning

confidence: 99%

Increase of COP for heat transformer in water purification systems. Part II – Without increasing heat source temperature

Romero

Siqueiros

Huicochea

2007

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

“…Single-stage, two-stage and double absorption heat transformers (DAHTs) operating with the water-lithium bromide mixture have been studied from the point of view of the first law of thermodynamics from Rivera et al [2,3] and Zhao et al [4]. It has been found that single-stage heat transformers are the most efficient with coefficients of *Correspondence to: W. Rivera, Centro de Investigacio´n en Energı´a, Universidad Nacional Auto´noma de Me´xico, A.P.34, 62580…”

Section: Introductionmentioning

confidence: 99%

Energy and exergy analysis of a double absorption heat transformer operating with water/lithium bromide

Martínez

Rivera

2009

Int. J. Energy Res.

Self Cite

View full text Add to dashboard Cite

SUMMARYIn the present study, the first and second law of thermodynamics have been used to analyze in detail the performance of a double absorption (lift) heat transformer operating with the water-lithium bromide mixture. A mathematical model was developed to estimate the coefficient of performance (COP), the exergy coefficient of performance (ECOP), the total exergy destruction in the system (C TD ) and the exergy destruction (C D ) in each one of the main components, as a function of the system temperatures, the efficiency of the economizer (EF EC ), the gross temperature lift and flow ratio (FR). The results showed that the generator is the component with the highest irreversibilities or exergy destruction contributing to about 40% of the total exergy destruction in the whole system, reason why this component should be carefully designed and optimized. The results also showed that the COP and ECOP increase with increase in the generator, the evaporator and the absorber-evaporator temperatures and decrease with the absorber and condenser temperatures. Finally, it was observed that the COP and ECOP are very dependent of the FR and the economizer efficiency (EF EC ) values. Also the optimum operating region of the analyzed system is shown in the present study.

show abstract

“…Rivera and Best (1994) has concluded that the double-stage heat transformer can boost the temperature in an absorber higher than that of a single-stage cycle, however its coefficient of performance, COP, would be less than that of the single-stage cycle. Ciambelli and Tufano (1988) developed a mathematical model for a double-stage heat transformer with water/sulphuric acid as the working fluid.…”

Section: Introductionmentioning

confidence: 95%

Comparison of energy, exergy, and entropy balance methods for analysing double-stage absorption heat transformer cycles

Fartaj

2004

Int. J. Energy Res.

View full text Add to dashboard Cite

SUMMARYThe energy, exergy and entropy balance methods are used to analyse a double-stage LiBr-water absorption heat transformer cycle. An energy balance comparing component energy transfer is used to determine energy calculations. An exergy balance is employed to evaluate exergy destruction, and an entropy balance to verify entropy generation. A comparison of the results by the second law exergy and entropy balances indicates that they are consistent in identifying the location and relative significance of key non-idealities within the system. The results obtained clearly show the influence of irreversibilities of individual components on deterioration of the effectiveness and the coefficient of performance of the system. The second law analysis offers an alternative view of cycle performance and provides an insight that the first law analysis cannot. The differences between the first law analysis by energy balance method and second law analysis by exergy and entropy balance methods are illustrated quantitatively for the double-stage absorption heat transformer cycle, and the limitations and advantages of these methods are presented and discussed.

show abstract

Thermodynamic study of advanced absorption heat transformers—I. Single and two stage configurations with heat exchangers

Cited by 51 publications

References 9 publications

Increase of COP for heat transformer in water purification systems. Part II – Without increasing heat source temperature

Increase of COP for heat transformer in water purification systems. Part II – Without increasing heat source temperature

Energy and exergy analysis of a double absorption heat transformer operating with water/lithium bromide

Comparison of energy, exergy, and entropy balance methods for analysing double-stage absorption heat transformer cycles

Contact Info

Product

Resources

About