Heat pump method and heat pump arrangement

Abstract

A heat pump method, in which a working medium is vaporized at a lower temperature level using a heat source and subsequently compressed and liquefied at an upper temperature level using a heat sink, wherein: after being vaporized and before being compressed, the working medium is superheated; a temperature increase caused by the compression is restricted by means of injection into the compression; and after being compressed and before being liquefied, the working medium is saturated at the upper temperature level. The present invention also relates to a corresponding heat pump arrangement.

1 . A heat pump method, in which a working medium is vaporized at a lower temperature level using a heat source and subsequently compressed and liquefied at an upper temperature level using a heat sink, wherein, after being vaporized and before being compressed, the working medium is superheated; a temperature increase caused by the compression is restricted by means of injection into the compression; and after being compressed and before being liquefied, the working medium is saturated at the upper temperature level. 
     
     
         2 . The heat pump method in accordance with  claim 1 , wherein: the lower temperature level (Tu) is 10 to 60° C.; the upper temperature level is at least 115° C.; an inlet temperature level into the compression is at most 10 K below the upper temperature level; and the temperature increase caused by the compression is restricted by means of injection to a temperature level of at most 180° C. 
     
     
         3 . The heat pump method in accordance with either  claim 1 , wherein the injection is carried out using a part of the working medium which is branched off from a remainder fed to superheating and then to compression before vaporization and before superheating, expanded, and fed to compression at one or more intermediate stages of compression. 
     
     
         4 . The heat pump method in accordance with  claim 1 , wherein a compressor configured as a single-shaft turbo compressor or screw compressor is used for compression. 
     
     
         5 . The heat pump method in accordance with  claim 1 , wherein saturation is carried out using a container from which a vapor phase is taken at the head side, at least partially liquefied in a heat exchanger thermally coupled to the heat sink, and fed back into the container. 
     
     
         6 . The heat pump method in accordance with  claim 5 , wherein the container is empty or equipped with trays and/or packings. 
     
     
         7 . The heat pump method in accordance with  claim 1 , which comprises a start-up operating mode and a subsequent operating mode carried out after the start-up operating mode, wherein the working medium in the subsequent operating mode is saturated at the upper temperature level and wherein the working medium in the start-up operating mode is cooled at least in part after compression using a further heat sink to an intermediate temperature level between the lower temperature level and the upper temperature level. 
     
     
         8 . The heat pump method in accordance with  claim 7 , wherein the further heat sink is thermally coupled to a start-up cooler. 
     
     
         9 . The heat pump method in accordance with  claim 8 , wherein the lower temperature level (Tu) is at least partially lowered in the start-up operating mode by passing a heating medium present at the lower temperature level first through the start-up cooler (E 4 ) and then through a heat exchanger (E 1 ) used for vaporizing the working medium. 
     
     
         10 . The heat pump method in accordance with  claim 1 , wherein the heat source is a condensing cooling medium of a refrigeration circuit, the heat of which at the lower temperature level is used at least in part to vaporize the working medium. 
     
     
         11 . The heat pump method in accordance with  claim 1 , wherein the working medium has a critical temperature which is at least 20° C. or 30° C. above the upper temperature level. 
     
     
         12 . The heat pump method in accordance with  claim 11 , wherein the working medium comprises one or more components selected from n-butane, i-pentane, n-pentane, cyclobutane and cyclopentane. 
     
     
         13 . The heat pump method in accordance with  claim 1 , wherein the heat source comprises a condensing refrigerant and/or a regenerated aqueous amine solution of an acid gas scrubber. 
     
     
         14 . A heat pump arrangement which is designed to vaporize a working medium at a lower temperature level using a heat source and subsequently to compress and liquefy said working medium at an upper temperature level, using a heat sink, wherein means are provided which are designed to superheat the working medium, after being vaporized and before being compressed, in order to restrict a temperature increase caused by the compression by means of injection into the compression, and to saturate the working medium, after being compressed and before being liquefied, at the upper temperature level. 
     
     
         15 . The heat pump arrangement in accordance with  claim 14 , which is designed to carry out a method, in which the working medium is vaporized at a lower temperature level using a heat source and subsequently compressed and liquefied at an upper temperature level using a heat sink, wherein, after being vaporized and before being compressed, the working medium is superheated; a temperature increase caused by the compression is restricted by means of injection into the compression; and after being compressed and before being liquefied, the working medium is saturated at the upper temperature level.