Heat pump

Abstract

A heat pump (100) having the following features is described: an evaporator (50) for evaporating a fluid in order to obtain an evaporated fluid, the evaporator (50) having an evaporator sump (52); a condenser (60) for condensing an evaporated fluid compressed by an N-stage compressor, the condenser (60) having a condensing sump (64), a condensation region (66) and a holding region (67) for holding vaporous fluid still remaining after the condensation region (66); the N-stage compressor which comprises N compressors, N being a natural number greater than or equal to one and the N-stage compressor being arranged between the evaporator (50) and the condenser (60); a vapour duct (30) which couples at least two of the N compressors of the N-stage compressor between the evaporator (50) and the condenser (60), and a vapour-conducting line (92) which is arranged between the condenser (60) and the evaporator (50) in order to conduct vaporous fluid out of the holding region (67) of the condenser (60) into the evaporator (50). Furthermore, methods for operating and producing the heat pump are described.

1 . A heat pump having the following features:
 an evaporator for evaporating a fluid in order to obtain an evaporated fluid, wherein the evaporator has an evaporator sump;   a condenser for condensing an evaporated fluid compressed by an N-stage compressor, wherein the condenser has a condenser sump, a condensation region and a holding region for holding vaporous fluid still remaining after the condensation region;   the N-stage compressor which comprises N compressors, wherein N is a natural number greater than or equal to one, wherein the N-stage compressor is arranged between the evaporator and the condenser;   a vapour duct which couples at least two of the N compressors of the N-stage compressor between the evaporator and the condenser, and a vapour-conducting line which is arranged between the condenser and the evaporator, in order to conduct vaporous fluid out of the holding region of the condenser into the evaporator.   
     
     
         2 . The heat pump according to  claim 1 , wherein the holding region is arranged in the condenser between the condensation region and the condenser sump comprising condensed working fluid, and wherein an opening of the vapour-conducting line is arranged in the holding region above a filling level of the working fluid in the condenser sump. 
     
     
         3 . The heat pump according to  claim 1 , wherein the condenser sump comprising condensed working fluid is arranged in the condenser, and wherein the vapour-conducting line extends from the holding region through the condenser sump and is conducted out of the condenser through a wall, preferably a base, of the condenser. 
     
     
         4 . The heat pump according to  claim 1 , wherein the condenser comprises a pipe bundle or a helical pipe arrangement, through which liquid to be heated can flow, wherein the pipe bundle or the helical pipe arrangement is arranged laterally with respect to the opening of the vapour-conducting line, and wherein an intake manifold of a compressor of the N-stage compressor is arranged above the pipe bundle or the helical pipe arrangement. 
     
     
         5 . The heat pump according to  claim 1 , in which the vapour-conducting line comprises an opening into the evaporator, wherein the opening is arranged above the evaporator sump, in the evaporator. 
     
     
         6 . The heat pump according to  claim 5 , wherein a pipe bundle for liquid to be cooled, and a sprinkling device for sprinkling the pipe bundle, are arranged in the evaporator, wherein the opening of the vapour-conducting line is arranged such that vaporous fluid which enter the evaporator through an opening strikes the pipe bundle laterally, and/or that the vaporous fluid which emerges from the vapour-conducting line enters a sprinkling region which is sprinkled at least in part by the sprinkling device. 
     
     
         7 . The heat pump according to  claim 1 , wherein each compressor of the N-stage compressor comprises its own shaft, on which the corresponding compressor of the N-stage compressor can be operated during operation. 
     
     
         8 . The heat pump according to  claim 1 , wherein the N-stage compressor comprises N compressors connected in series, wherein the vapour-conducting line is a single vapour-conducting line and conducts the vaporous fluid, brought into the condenser by a last stage, from the condenser into the evaporator. 
     
     
         9 . The heat pump according to  claim 1 , wherein at least two compressors of the N-stage compressor are connected via a vapour duct and in each case an intermediate cooler is arranged between two compressors, in order to cool the vaporous fluid. 
     
     
         10 . The heat pump according to  claim 9 , wherein the intermediate cooler is arranged in a sink of the vapour duct and the intermediate cooler comprises an intermediate cooling sump and an effect element, wherein the effect element is configured to bring about an interaction between an intermediate cooling fluid that can flow through a fluid line from the intermediate cooling sump or from the evaporator sump or from the condenser sump into the effect element, and a heated vaporous fluid that can be output from the compressor, wherein the interaction, in particular brings about cooling of the vaporous fluid, discharged from the compressor, by the intermediate cooling fluid. 
     
     
         11 . The heat pump according to  claim 10 , wherein each intermediate cooler comprises an intermediate cooling sump and an effect element and is arranged in its own sink in the vapour duct, and comprises its own first intermediate cooler line. 
     
     
         12 . The heat pump according to  claim 9 , wherein the vapour duct has a curved shape, comprising the sink, between two compressors, such that fluid from the vapour duct flows past the intermediate cooling sump. 
     
     
         13 . The heat pump according to  claim 9 , wherein the vapour-conducting line and the vapour duct are fluidically separated from one another. 
     
     
         14 . The heat pump according to  claim 1 , wherein further N compressors are arranged such that a further compressor of the N compressors is connected in series with a first compressor of the N-stage compressor, by switching a switch into an open state. 
     
     
         15 . The heat pump according to  claim 1 , wherein a bridging flap is arranged in the vapour-conducting line, which flap can be transferred into an open position for conducting the vaporous fluid from the condenser to the evaporator, an intermediate position, or into a closed position for preventing conduction of the vaporous fluid into the evaporator. 
     
     
         16 . The heat pump according to  claim 15 , wherein the bridging flap is configured as a controlled bridging valve which can be addressed by means of a controller, in order to be operated close to a boundary line of a compressor characteristic diagram assigned to one of the N-stage compressor. 
     
     
         17 . The heat pump according to  claim 16 , wherein the compressor characteristic diagram assigned to the N-stage compressor defines a relationship between a pressure ratio and a mass flow, wherein in the case of the compressor characteristic diagram the pump limit is present, which shows a monotonically increasing function between the mass flow and the pressure ratio, and, wherein the bridging flap is controlled, in order to ensure that, for a particular mass flow, the pressure ratio is smaller than a limit pressure ratio which, according to the function, is assigned to the determined mass flow. 
     
     
         18 . The heat pump according to  claim 16 , wherein the controller is configured to transfer the bridging flap into a closed position, into an open position, or into an intermediate position, in order to hold a load of the N-stage compressor at least at a load target value, during operation. 
     
     
         19 . The heat pump according to  claim 16 , wherein the controller is configured to
 open the bridging flap if the load of the N-stage compressor falls below the load target value; or   close the bridging flap if the load of the N-stage compressor exceeds the load target value, in order to create an additional load; or   control the intermediate position of the bridging flap depending on falling below the load target value.   
     
     
         20 . The heat pump according to  claim 18 , wherein the load target value specifies a load of the heat pump during operation, which is to be achieved at least by the N-stage compressor. 
     
     
         21 . The heat pump according to  claim 16 , wherein in the case of a two-stage compressor the second compressor is deactivated when the bridging flap is opened, or, in the case of a multi-stage compressor all stages apart from the first compressor stage are deactivated when the bridging flap is opened. 
     
     
         22 . A method for operating a heat pump comprising an evaporator for evaporating a fluid, in order to obtain an evaporated fluid, wherein the evaporator has an evaporator sump; a condenser for condensing an evaporated fluid compressed by an N-stage compressor, wherein the condenser has a condenser sump, a condensation region and a holding region for holding a vaporous fluid still remaining after the condensation region; the N-stage compressor which comprises N compressors, wherein N is a natural number greater than or equal to one, wherein the N-stage compressor is arranged between the evaporator and the condenser; a vapour duct which couples at least two of the N compressors of the N-stage compressor between the evaporator and the condenser, and a vapour-conducting line which is arranged between the condenser and the evaporator, in order to conduct vaporous fluid out of the holding region of the condenser into the evaporator, which method comprises the following steps:
 evaporating fluid by the evaporator;   supplying the evaporated fluid into the first compressor stage, in order to compress the evaporated fluid;   conducting the compressed fluid through the vapour duct, in order to pass the N compressors, in order to ultimately reach the condenser;   condensing the compressed fluid in the condensation region and holding non-condensed fluid in the holding region; and   returning the evaporated fluid via the vapour-conducting line out of the holding region and to the evaporator.   
     
     
         23 . A method for producing a heat pump comprising an evaporator for evaporating a fluid, in order to obtain an evaporated fluid, wherein the evaporator has an evaporator sump; a condenser for condensing an evaporated fluid compressed by an N-stage compressor, wherein the condenser has a condenser sump, a condensation region and a holding region for holding a vaporous fluid still remaining after the condensation region; the N-stage compressor which comprises N compressors, wherein N is a natural number greater than or equal to one, wherein the N-stage compressor is arranged between the evaporator and the condenser; a vapour duct which couples at least two of the N compressors of the N-stage compressor between the evaporator and the condenser, and a vapour-conducting line which is arranged between the condenser and the evaporator, in order to conduct vaporous fluid out of the holding region of the condenser into the evaporator, which method comprises the following steps:
 arranging the evaporator of the N-stage compressor and of the condenser;   connecting the evaporator, of the N-stage compressor and of the condenser via the vapour duct; and   connecting the evaporator and the condenser via the vapour-conducting line, in order to create a circuit in which the fluid circulates.