A model for analysis and design of H2O–LiBr absorption heat pumps

Bakhtiari, Bahador; Fradette, Louis; Legros, Robert; Paris, Jean

doi:10.1016/j.enconman.2010.09.037

Cited by 87 publications

(27 citation statements)

References 14 publications

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“…Internal heat transfer coefficient for evaporator, condenser, generator and absorber are determined from Gnielinski correlation [31] whereas Dobson and Chato correlation [32] is used for computation of internal heat transfer coefficient of cascade condenser. Bakhitari et al [27] produced a new correlation for computation of external heat transfer coefficient at generator by integrating experimental results obtained by Wang et al [33] and same is used in present study. Holman [34] and Hoffmann et al [35] correlations are used for determining external heat transfer coefficient at condenser and absorber respectively; in the case of evaporator the corresponding correlation developed by Rohesnow [36] is used [27].…”

Section: Design Of Heat Exchangersmentioning

confidence: 88%

“…Bakhitari et al [27] produced a new correlation for computation of external heat transfer coefficient at generator by integrating experimental results obtained by Wang et al [33] and same is used in present study. Holman [34] and Hoffmann et al [35] correlations are used for determining external heat transfer coefficient at condenser and absorber respectively; in the case of evaporator the corresponding correlation developed by Rohesnow [36] is used [27]. External heat transfer coefficient at cascade condenser is obtained by applying Rohesnow correlation [36] as proposed in literature [29].…”

Section: Design Of Heat Exchangersmentioning

confidence: 88%

“…For solution heat exchanger, the outside pipe diameter is taken 15 mm with 1 mm wall thickness and 9.5 mm inside pipe diameter with 0.7 mm wall thickness [28]. The pipe material for all the heat exchanger is assumed to be copper [27]. For given heat load ð _ Q Þ, the total surface area (A) required for each heat exchanger is calculated from the following simple expression and total number of tubes is obtained for the given values of the physical dimensions of each unit.…”

Section: Design Of Heat Exchangersmentioning

confidence: 99%

“…[29]. The other dimensioning parameters (Table 1) of various heat exchangers of present cascaded system are selected as cited in literature [27,29]. For solution heat exchanger, the outside pipe diameter is taken 15 mm with 1 mm wall thickness and 9.5 mm inside pipe diameter with 0.7 mm wall thickness [28].…”

Section: Design Of Heat Exchangersmentioning

confidence: 99%

“…The design methodology of components of VCACRS is followed as per the procedure and correlations described in Ref. [27][28][29]. Bakhtiar et al [27] designed the evaporator, condenser, absorber and generator of VARS as shell and tube heat exchanger for water chilling application whereas the design of solution heat exchanger was done as single pass annular heat exchanger given in Ref.…”

Section: Design Of Heat Exchangersmentioning

confidence: 99%

See 4 more Smart Citations

NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

Jain

Sachdeva

Kachhwaha

2015

Energy Conversion and Management

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Section: Design Of Heat Exchangersmentioning

confidence: 88%

Section: Design Of Heat Exchangersmentioning

confidence: 88%

Section: Design Of Heat Exchangersmentioning

confidence: 99%

Section: Design Of Heat Exchangersmentioning

confidence: 99%

Section: Design Of Heat Exchangersmentioning

confidence: 99%

See 3 more Smart Citations

NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

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Performance characteristics of an ammonia-water absorption heat pump system

Gadalla

Ibrahim

Hassan

2013

Int. J. Energy Res.

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SUMMARY The influences of the performance parameters and the heat transfer characteristics of the absorption heat pump using ammonia–water mixture are theoretically carried out. There is a pronounced effect of the ammonia concentration ξ after rectifier on the temperature glides that has been investigated. At ξ = 0.9000 and saturation pressures of 75 and 0.5 bar, the temperature glides are 64.4°C and 81.21°C, respectively, whereas these glides are 0°C and 16.1°C at ξ = 0.9999 and at the same pressures. This mixture property considerably affects the absorption system performance and the design of the rectifier as well as other absorption components. A correlation of the Nusselt number, Nu, is developed and compared with some published work in the literature for plate type heat exchanger. The effects of ammonia concentration ξ, mass fraction spread Δξ, specific solution circulation ratio f, and pressure ratio Rp on the refrigerant mass flow rate, the pressure drop, and the heat transfer coefficients during the condensation, the evaporation, and the absorption processes are investigated. It was found that increasing ammonia mass fraction spread Δξ results in both specific circulation ratio f and Rp that have insignificant effects on the refrigerant mass flow rate. Mounting Δξ at constant f reduces the pressure drop gradually and subsequently starts to increase as Δξ escalates. The ammonia concentration ξ has insignificant effect on the evaporation heat transfer coefficient but has a little effect on the condensation and the absorber heat transfer coefficients. The ammonia mass fraction spread Δξ and f have considerable effects on the heat transfer coefficient for different absorption heat pump components. Rp has a pronounced effect on the evaporation heat transfer coefficient, although it has a slight effect on the condensation and the absorber heat transfer coefficients. The effect of Rp on the heat transfer coefficient may be eliminated in the absorber for Δξ > 0.18. Copyright © 2013 John Wiley & Sons, Ltd.

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Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

2019

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Summary Refrigerants bearing high global warming potential (GWP) and ozone depletion potential (ODP) were outlawed or facing time‐beared permission under the Montreal (1987), Kyoto (1997) protocols, F‐Gas law (2015), Paris Accord (2016), and recent Kigali Amendment to Montreal Protocol (2019). In order to modify followed by the paradigm shift of existing heating and cooling systems, American Society of Heating, Refrigeration, and Air‐Conditioning Engineers (ASHRAE) envisaged natural and synthetic refrigerants (Synrefs) are under investigation globally. Carbon dioxide (CO2) is a popular natural refrigerant (Natref) replacing Synrefs used in commercial heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems globally. A rampant rise is observed in markets of Asia (Japan and China), North America (the United States and Canada), the Australian continent, and Africa (South Africa) by reaching 20 000 CO2‐stores around the globe. The European markets are leading the utilization of CO2 in the heat pump, and refrigeration, CO2 based markets estimate 14% of the total food retail stores (400 m2). Japan is the second leading market of CO2 heat pump and refrigeration with more than 10 200 CO2 condensing units. CO2 transcritical systems have a share of more than 10% in only European market (large stores); however, their share is less than 10% of total stores in other major markets of the world. New pump and compressor‐driven transcritical CO2 systems integrate ejectors, condensers, and booster systems to reduce energy consumptions, enhance efficiency, efficacy, and coefficient of performance. This article reports a critical review of the CO2 based heating, cooling, and refrigeration system and presents updated literature along with barriers and challenges on commercial use of Natref‐based heating and cooling applications worldwide.

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A model for analysis and design of H2O–LiBr absorption heat pumps

Cited by 87 publications

References 14 publications

NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

Performance characteristics of an ammonia-water absorption heat pump system

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

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A model for analysis and design of H2O–LiBr absorption heat pumps

Cited by 87 publications

References 14 publications

NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

Performance characteristics of an ammonia-water absorption heat pump system

Review of carbon dioxide (CO 2 ) based heating and cooling technologies: Past, present, and future outlook

Contact Info

Product

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About

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook