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international journal of refrigeration 32 (2009) 47–57

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A combined double-way chemisorption refrigeration cycle based on adsorption and resorption processes
T.X. Li, R.Z. Wang*,1, R.G. Oliveira, J.K. Kiplagat, L.W. Wang
Institute of Refrigeration and Cryogenics, Shanghai Jiao TongUniversity, 800 Dongchuan Road, Shanghai 200240, China

article info
Article history: Received 26 February 2008 Received in revised form 30 May 2008 Accepted 17 July 2008 Published online 5 August 2008 Keywords: Adsorption system Resorption Ammonia Chloride Manganese Barium Additive Graphite Design Thermodynamic cycle Experiment COP

abstract
An innovative combined double-way chemisorptionrefrigeration cycle based on adsorption and resorption processes is presented. Two different reactive salts were used as sorbents and ammonia was utilized as the refrigerant in the proposed cycle. The useful cold was obtained from the evaporation heat of the refrigerant during the adsorption process and from the reaction heat of the low-temperature salt during the resorption process. The proposedcombined double-way cycle has a distinct advantage of higher coefficient of performance (COP) in comparison with conventional adsorption cycle or resorption cycle. Experimental verification indicated that the advanced combined doubleway cycle is feasible for refrigeration application, and the ideal COP of the basic cycle was about 1.24. Theoretical results showed that the proposed combined double-waycycle could improve COP by 167% and 60% when compared with conventional adsorption cycle and resorption cycle, respectively. ª 2008 Elsevier Ltd and IIR. All rights reserved.

` ´ ´ ´ Cycle frigorifique a sorption/chimique fonde sure les procedes ` ` ´ a adsorption a resorption
´s ` ` ´ ` Mots cle : Systeme a adsorption ; Resorption ; Ammoniac ; Chlorure ; Manganese ; Baryum ; Additif ;Graphite ; Conception ; Cycle ´ thermodynamique ; Experimentation ; COP

* Corresponding author. Tel./fax: þ86 21 34206548. E-mail address: rzwang@sjtu.edu.cn (R.Z. Wang). 1 IIR-B2 vice president and member of IIR strategic committee. 0140-7007/$ – see front matter ª 2008 Elsevier Ltd and IIR. All rights reserved. doi:10.1016/j.ijrefrig.2008.07.007

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international journal of refrigeration 32(2009) 47–57

Nomenclatures cross-section area of evaporator (m2) coefficient of performance specific heat of expanded graphite (kJ kgÀ1 KÀ1) specific heat of high-temperature salt (kJ kgÀ1 KÀ1) specific heat of low-temperature salt (kJ kgÀ1 KÀ1) specific heat of metallic reactor (kJ kgÀ1 KÀ1); enthalpy of refrigerant at condensation temperature (kJ molÀ1) He(TEv) enthalpy of refrigerant atevaporation temperature (kJ molÀ1) L(t) liquid level inside the evaporator during the synthesis phase (m) liquid level inside the evaporator at the beginning L(t0) of the synthesis phase (m) molar mass of high-temperature salt (g molÀ1) MHTS molar mass of low-temperature salt (g molÀ1) MLTS amount of ammonia adsorbed by reactive salt mad(t) ðkgNH3 kgÀ1 Þ salt mass of expanded graphite (kg) mEG mass ofhigh-temperature metallic reactor (kg) mHR mass of low-temperature metallic reactor (kg) mLR mass of reactive salt (kg) mS constraint pressure (Pa) Pc evaporation pressure (Pa) Pe Peq(Teq) equilibrium pressure (Pa) high pressure (Pa) PH low pressure (Pa) PL Qdes-HTS desorption heat of high-temperature salt (kJ) Qevap-cooling useful cooling during the adsorption phase (kJ) Qres-cooling usefulcooling during the resorption phase (kJ) adsorption temperature of high-temperature Ta-H salt (K) AEv COP Cp-EG Cp-HTS Cp-LTS Cp-R Hc(TCn)

adsorption temperature of low-temperature salt (K) constraint temperature (K) Tc desorption temperature of high-temperature Td-H salt (K) desorption temperature of low-temperature Td-L salt (K) evaporation temperature (K) Te Teq(Peq) equilibrium temperature (K)...