Absorption heat pump with sorbent comprising lithium chloride and an organic chloride salt

Abstract

An absorption heat pump with a sorbent which comprises lithium chloride and at least one salt Q + Cl − with an organic cation Q + and the shared anion chloride, the organic cation Q + having a molar mass of not more than 200 g/mol, exhibits an improved degassing range of the working medium composed of refrigerant and sorbent.

1 - 12 . (canceled) 
     
     
         13 . An absorption heat pump comprising an absorber, a desorber, a condenser, an evaporator, a volatile refrigerant and a sorption medium, wherein said sorption medium comprises lithium chloride and at least one salt Q + Cl −  comprising an organic cation Q +  and the shared anion chloride, and wherein the organic cation Q +  has a molar mass of not more than 200 g/mol. 
     
     
         14 . The absorption heat pump of  claim 13 , wherein the sorption medium contains lithium chloride and the salt Q + Cl −  in a molar ratio at which the melting point of the mixture of lithium chloride and salt Q + Cl −  is lower than the melting points of the components lithium chloride and Q − Cl − . 
     
     
         15 . The absorption heat pump of  claim 14  wherein the sorption medium contains lithium chloride and the salt Q + Cl −  in a molar ratio which deviates by not more than 25% from the molar ratio of a eutectic mixture of lithium chloride and the salt Q + Cl − . 
     
     
         16 . The absorption heat pump of  claim 13 , wherein the proportion of lithium chloride and the salt Q + Cl −  in the sorption medium is more than 50% by weight. 
     
     
         17 . The absorption heat pump of  claim 13 , wherein the refrigerant is selected from the group consisting of: methanol, ethanol, 2-propanol, trifluoroethanol, sulphur dioxide, carbon dioxide and ammonia. 
     
     
         18 . The absorption heat pump of  claim 13 , wherein the refrigerant is water. 
     
     
         19 . The absorption heat pump of  claim 13 , wherein a solution of lithium chloride in the refrigerant which is saturated at 35° C. has a higher vapour pressure than a mixture of the salt Q + Cl −  and the refrigerant having the same proportion by weight of refrigerant. 
     
     
         20 . The absorption heat pump of  claim 13 , wherein the organic cation Q +  is selected from the group consisting of: 1,3 dialkylimidazolium ions; 1,3-dialkyl-imidazolinium ions; N-alkylpyridinium ions; N,N-dialkylpyrrolidinium ions; and ammonium ions having the structure R 1 R 2 R 3 R 4 N + , wherein R 1 , R 2  and R 3  are each, independently of one another, hydrogen, alkyl or hydroxyethyl and R 4  is an alkyl radical. 
     
     
         21 . The absorption heat pump of  claim 13 , wherein said absorption heat pump is operated as absorption refrigeration machine and heat is taken up in the evaporator from a medium to be cooled. 
     
     
         22 . The absorption heat pump of  claim 13 , wherein said absorption heat pump has a two-stage construction. 
     
     
         23 . The absorption heat pump of  claim 13 , wherein a vapour phase containing refrigerant and a liquid phase containing sorption medium are separated from one another by a semipermeable membrane in the absorber and/or desorber and the semipermeable membrane is permeable to the refrigerant and impermeable to the sorption medium. 
     
     
         24 . The absorption heat pump of  claim 13 , wherein at least one of the components absorber, desorber, condenser and evaporator has a wall surface made of a polymeric material selected from among polyamides, polyimides and polyether ether ketone via which heat is exchanged with the surroundings. 
     
     
         25 . The absorption heat pump of  claim 15 , wherein the proportion of lithium chloride and the salt Q + Cl −  in the sorption medium is more than 50% by weight. 
     
     
         26 . The absorption heat pump of  claim 25 , wherein the refrigerant is selected from the group consisting of: methanol, ethanol, 2-propanol, trifluoroethanol, sulphur dioxide, carbon dioxide and ammonia. 
     
     
         27 . The absorption heat pump according of  claim 25 , wherein the refrigerant is water. 
     
     
         28 . The absorption heat pump of  claim 17 , wherein the organic cation Q +  is selected from the group consisting of: 1,3 dialkylimidazolium ions; 1,3-dialkyl-imidazolinium ions; N-alkylpyridinium ions; N,N-dialkylpyrrolidinium ions; and ammonium ions having the structure R 1 R 2 R 3 R 4 N + , wherein R 1 , R 2  and R 3  are each, independently of one another, hydrogen, alkyl or hydroxyethyl and R 4  is an alkyl radical. 
     
     
         29 . The absorption heat pump of  claim 18 , wherein the organic cation Q +  is selected from the group consisting of: 1,3 dialkylimidazolium ions; 1,3-dialkyl-imidazolinium ions; N-alkylpyridinium ions; N,N-dialkylpyrrolidinium ions; and ammonium ions having the structure R 1 R 2 R 3 R 4 N + , wherein R 1 , R 2  and R 3  are each, independently of one another, hydrogen, alkyl or hydroxyethyl and R 4  is an alkyl radical. 
     
     
         30 . The absorption heat pump of  claim 29 , wherein a vapour phase containing refrigerant and a liquid phase containing sorption medium are separated from one another by a semipermeable membrane in the absorber and/or desorber and the semipermeable membrane is permeable to the refrigerant and impermeable to the sorption medium. 
     
     
         31 . The absorption heat pump of  claim 30 , wherein the proportion of lithium chloride and the salt Q + Cl −  in the sorption medium is more than 50% by weight. 
     
     
         32 . The absorption heat pump of  claim 31 , wherein the sorption medium contains lithium chloride and the salt Q + Cl −  in a molar ratio which deviates by not more than 25% from the molar ratio of a eutectic mixture of lithium chloride and the salt Q + Cl − .