EP3830500A2 - Circuit frigorifique - Google Patents

Circuit frigorifique

Info

Publication number
EP3830500A2
EP3830500A2 EP19746487.8A EP19746487A EP3830500A2 EP 3830500 A2 EP3830500 A2 EP 3830500A2 EP 19746487 A EP19746487 A EP 19746487A EP 3830500 A2 EP3830500 A2 EP 3830500A2
Authority
EP
European Patent Office
Prior art keywords
expansion
unit
mass flow
pressure
refrigerant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19746487.8A
Other languages
German (de)
English (en)
Inventor
Oliver Javerschek
Julian KARBINER
Jörg Nickl
Jens MANNEWITZ
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bitzer Kuehlmaschinenbau GmbH and Co KG
Original Assignee
Bitzer Kuehlmaschinenbau GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bitzer Kuehlmaschinenbau GmbH and Co KG filed Critical Bitzer Kuehlmaschinenbau GmbH and Co KG
Publication of EP3830500A2 publication Critical patent/EP3830500A2/fr
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B11/00—Compression machines, plants or systems, using turbines, e.g. gas turbines
    • F25B11/02—Compression machines, plants or systems, using turbines, e.g. gas turbines as expanders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/04—Refrigeration circuit bypassing means
    • F25B2400/0411—Refrigeration circuit bypassing means for the expansion valve or capillary tube
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/05—Compression system with heat exchange between particular parts of the system
    • F25B2400/053—Compression system with heat exchange between particular parts of the system between the storage receiver and another part of the system
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/07—Details of compressors or related parts
    • F25B2400/075—Details of compressors or related parts with parallel compressors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/13—Economisers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/14—Power generation using energy from the expansion of the refrigerant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/16—Receivers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/13—Vibrations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2509—Economiser valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19—Pressures
    • F25B2700/193—Pressures of the compressor
    • F25B2700/1931—Discharge pressures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19—Pressures
    • F25B2700/193—Pressures of the compressor
    • F25B2700/1933—Suction pressures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2115—Temperatures of a compressor or the drive means therefor
    • F25B2700/21151—Temperatures of a compressor or the drive means therefor at the suction side of the compressor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2115—Temperatures of a compressor or the drive means therefor
    • F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor

Definitions

  • the invention relates to a refrigerant circuit, comprising at least one refrigerant compressor, which compresses refrigerant supplied to a suction connection to high pressure, so that a compressor mass flow of the refrigerant compressed to high pressure emerges at a pressure port, at least one high-pressure-side heat-emitting heat exchanger with an inlet at which the refrigerant circuit feeds the compressor mass flow, and with an outlet from which a cooled total mass flow of refrigerant emerges, at least one expansion unit, comprising an activatable or deactivatable expansion compression unit having an expander and a compressor stage, which expansion unit has an expansion unit that moves from the refrigerant circuit towards the suction port of the refrigerant.
  • compressor-led expansion mass flow of the total mass flow expanded from high pressure to an expansion pressure and at least one cooling stage with at least one w heat-absorbing heat exchanger, to which the refrigerant circuit supplies a main mass flow comprised by the expansion pressure mass flow expanded by the expansion unit and, after leaving the cooling stage, feeds this main mass flow to the suction connection of the refrigerant compressor.
  • this object is achieved in that the refrigerant circuit is assigned an operating adaptation unit which comprises a bypass line which can be activated, deactivated and which bypasses the expansion compression unit, and that the operating adaptation unit in the case of a suboptimal operating state, the expansion unit transfers the bypass line from an inactive state to an active state in which it generates a bypass of the high-pressure refrigerant bypass mass flow for the cooling stage, and supplies the refrigerant circuit for forwarding to the cooling stage.
  • the operational adaptation unit according to the invention solves the problem that if the expansion unit, in particular the expansion compression unit, is unstable, the refrigerant circuit is no longer functional or can only function to a very limited extent, so that it does not can provide sufficient cooling capacity on the cooling unit and thus the in
  • the invention provides the possibility of either deactivating the operating adaptation unit and activating the expansion compression unit or deactivating the expansion compression unit and activating the operating adaptation unit or operating both the expansion compression unit and the operating adaptation unit activated in parallel.
  • Operating adaptation unit supplies the diversion mass flow directly or indirectly to an expansion line of the refrigerant circuit that receives it.
  • bypass line does not necessarily have to flow directly into the expansion line, but can also open into the refrigerant circuit before the expansion line, provided that it is ensured that the bypass mass flow is indirectly fed to the expansion line.
  • bypass line feeds the bypass mass flow to a line of the refrigerant circuit carrying the expansion pressure mass flow which is at expansion pressure during normal operation of the refrigerant circuit.
  • Ambient temperature influenced temperature recorded on the high pressure side, heat emitting heat exchanger.
  • Operating adaptation unit is carried out in such a way that the operating adaptation unit at a detected temperature which is above a temperature threshold required for a stable operating state of the expansion unit
  • the operating adaptation unit is activated such that the operating adaptation unit activates the bypass line at a detected temperature that is below a temperature threshold necessary for a stable operating state of the expansion unit.
  • the operating adaptation unit is activated such that the operating adaptation unit deactivates the expansion unit after the bypass line has been activated, in order to prevent unstable operating states of the latter.
  • Operational adaptation unit takes place in such a way that the operational adaptation unit switches off the expansion unit with a delay after the bypass line is activated, so that there is no abrupt transition of the refrigerant circuit from operation with the expansion unit to operation with activated bypass line of the operational adaptation unit, but rather through the delayed deactivation of the expansion unit Period with a parallel operation of the expansion unit and the operating adaptation unit is present, which also prevents unstable operating states.
  • Operational adaptation unit takes place in such a way that the operational adaptation unit at a detected temperature, which is below a lower temperature threshold, which is lower than the temperature threshold for activating the
  • bypass line the bypass line activated or deactivated according to a pulse width modulation.
  • This solution has the advantage that at very low ambient temperatures there is a very strong reduction in the high pressure, which can be counteracted by the fact that the bypass line of the operating adaptation unit is operated with pulse width modulation in order to prevent a reduction in the high pressure.
  • An advantageous solution provides for a control of the operating adaptation unit to be detected based on an expansion fault in the expansion unit.
  • Such an expansion disturbance can be detected by various pressure and temperature sensors.
  • the operating adaptation unit is activated by the high pressure of the total mass flow or the
  • an advantageous solution provides that the operating adaptation unit is controlled based on a pressure difference between the high pressure of the total mass flow and / or the expansion mass flow before it enters the expander and a line section of the refrigerant circuit which is at expansion pressure.
  • a differential pressure is thus detected for the control of the operating adaptation unit.
  • the operating adaptation unit is activated based on the high pressure of the total mass flow or the expansion mass flow before it enters the expander with regard to its absolute value.
  • a pressure sensor is provided, for example.
  • the operating adaptation unit is activated based on a comparison of the high pressure of the
  • Operating adaptation unit activated and / or deactivated.
  • Such a control compares the detected high pressure of the total mass flow or the expansion mass flow before it enters the expander with a stored reference pressure, for example.
  • bypass line can be activated and deactivated by means of a switching valve, such a switching valve only changing between two states, namely the open and the closed state, so that no control of the size of the mass flow through the bypass line is possible is.
  • this solution allows the switching valve to be designed so that, when activated, it allows the bypass mass flow to pass through without pressure loss, so that an optimally large mass flow flows through the bypass line and any pressure drop can be avoided.
  • an advantageous solution provides that at least one expansion element is functionally assigned to the bypass line, which is active in the activated state of the bypass line and permits control or regulation of the mass flow, that is to say the size of the mass flow.
  • Such an expansion element works like a conventional expansion element and is able to connect the expansion unit with the
  • the operating adaptation unit parallel to the expansion unit Possibility of operating the operating adaptation unit parallel to the expansion unit, for example in all cases in which the total mass flow in the refrigerant circuit is greater than the mass flow flowing through the expansion unit, so that an increase in the high pressure cannot be prevented.
  • the operating adaptation unit with the expansion element opens up the possibility of counteracting such an increase in the high pressure in a controlled manner and thus regulating the high pressure to a desired high pressure level.
  • the operating adaptation unit comprises at least one switch-off element for switching off the expansion compression unit. This ensures that, for example, a leak in the expansion compression unit no longer interferes with the function of the refrigerant circuit and faulty operation of the expander and compressor stage does not cause a malfunction in the refrigerant circuit, which may counteract the function of the operating adaptation unit or could also disrupt it.
  • An advantageous solution provides that the shutdown element of the operating adaptation unit is arranged either in front of an expander inlet or after an expander outlet, so that there is primarily the possibility of switching off the expander of the expansion compression unit.
  • an advantageous solution provides that a switching element is arranged in the bypass line of the operating adaptation unit, which produces a direct or indirect connection between an expansion element for generating the supercooling mass flow of the expansion unit and an expansion pressure output connection of the expansion unit.
  • This solution has the advantage that an expansion element, which is present in the expansion unit anyway, for generating a supercooling mass flow can be used by the operating adaptation unit to generate the bypass mass flow instead of the subcooling mass flow, so that no additional one is generated in the operating adaptation unit
  • the switching element with the
  • Control of the operating adaptation unit is controllable.
  • the switching element is a switching valve.
  • Another advantageous solution provides that the switching element is a
  • 3/2 way valve is either the bypass line or a
  • Expander outlet connects to the expansion pressure outlet connection.
  • a 3/2-way valve is preferably also used to close the expander outlet when the bypass line is connected to the expansion pressure outlet connection or to close the bypass line when the expander outlet is connected to the expansion pressure outlet connection.
  • a further solution to the problem according to the invention provides that a pulsation damper unit is arranged in the refrigerant circuit.
  • Such a pulsation damper unit has the great advantage that it is able to dampen pulsations, in particular pulsations generated by the expansion compression unit, in order to prevent damage and / or noise in the refrigerant circuit caused by such pulsations.
  • a variant of such a pulsation damper unit provides that it has a damper housing enclosing a damper chamber, in which at least one gas bubble is formed from refrigerant and that the gas bubble leads to a line of the refrigerant circuit
  • Pulsation transmission line picks up pulsations and is able to dampen them.
  • the gas bubble is above a refrigerant bath and, in this case in particular, there is liquid refrigerant in the pulsation transmission line, which transmits the pulsations into the refrigerant bath from liquid refrigerant ,
  • the pulsation damper unit is provided with a heater for maintaining the gas bubble made of refrigerant, so that this can also ensure that the refrigerant circuit is operated subcritically there is always a sufficient size of the gas bubble that dampens pulsations in the pulsation damper unit.
  • the pulsation damper unit is heated
  • a pulsation damper unit has a damper housing with a piston movable in it and two chambers adjacent to the piston on opposite sides and separated from one another by the piston, and that in at least one of the chambers there is a gas bubble made of refrigerant formed.
  • the piston serves to dampen at least one of the gas bubbles that form in at least one of the chambers
  • the piston itself in the damper housing is additionally acted upon by elastic elements, for example springs, which hold the piston in an initial position, from which the piston then acts to dampen pulsations against the force of the elastic force Elements can move.
  • elastic elements for example springs
  • each of the chambers is connected to different flows of refrigerant lines of the refrigerant circuit by means of a pulsation transmission line.
  • Such a pulsation damper unit thus serves, in particular, to dampen pulsations by using a connection between different flows of refrigerant lines, which for example can also be at different pressure levels,
  • Lines can be transmitted and thus, in addition to the piston itself, a damping effect occurs due to the coupling of the different flows of lines carrying refrigerant.
  • one pulsation transmission line is connected directly or indirectly to an input of the heat-emitting heat exchanger and the other pulsation transmission line is connected directly or indirectly to an output of the heat-emitting heat exchanger.
  • the damping effect of such a pulsation damper unit can be further improved if at least one pulsation transmission line is coupled to the refrigerant circuit via a throttle.
  • the task mentioned at the outset is also achieved in that between the
  • an intermediate pressure collector is arranged in the bath, a liquid phase of the refrigerant collects and in the gas volume above the bath, a gas phase of the
  • Refrigerant collects.
  • the liquid phase is preferably fed to the cooling stage for expansion in the expansion element thereof.
  • the intermediate pressure collector has the advantage that additional subcooling can be achieved in the intermediate pressure collector by the refrigerant kept at intermediate pressure.
  • an additional mass flow is removed from the gas volume of the intermediate pressure collector.
  • Such an additional mass flow can in particular be via
  • the cooling stage is connected to a freezer stage in the form of a booster.
  • the provision of an intermediate pressure collector and an expansion element for controlling the additional mass flow discharged from the intermediate pressure collector furthermore makes it possible to regulate an intermediate pressure in the intermediate pressure collector to a specific pressure value by means of an intermediate pressure control which controls the expansion element.
  • regulation is usually carried out to a fixed pressure value of the intermediate pressure, which is in particular independent of the regulation or control of the high pressure in the total mass flow, which is carried out via the control assigned to the expansion unit.
  • the COP coefficient of performance
  • the ratio of cooling power to mechanical power used, in particular in
  • the intermediate pressure control which controls the expansion element detects the pressure and / or the temperature of the total mass flow in the high-pressure discharge line and the size of the inlet pressure of the compressor stage and controls the intermediate pressure in such a way that a predefined quantity suitable for these is determined Value of the inlet pressure.
  • the pressure value at which the intermediate pressure in the intermediate pressure collector is regulated by the intermediate pressure control is based on your basic value, for example a value in the range from 30 bar to 45 bar in the case of CO2 as a refrigerant, and additional values with amounts, for example in the range from 0.5 bar to 7 bar in the case of CO2 as a refrigerant.
  • This solution has the advantage that additional efficiency increases are possible by adapting the intermediate pressure and, for example, thus also due to the reaction on the expansion unit, in particular on an inlet pressure of the compressor stage.
  • the surcharge values have positive values in summer operation and negative values in winter operation, the amounts of the surcharge values being in the range mentioned above.
  • the size of the additional values is dependent on the values of the high pressure that arise when regulating the high pressure.
  • the additional values are higher for high values of the high pressure than for low values of the high pressure.
  • the amounts of the surcharge values are in the range from 0.5 bar to 7 bar.
  • expansion unit itself, no further details have been given, except that it comprises an expansion compression unit with an expander and a compressor stage.
  • a further solution to the above-mentioned task provides an energetically highly efficient refrigerant circuit, the expansion unit having a subcooling unit for subcooling at least the expansion mass flow of the refrigerant supplied to the expansion unit, that the expansion unit comprises the expansion compression unit
  • supercooling mass flow supplies the compressor stage, which in turn compresses the subcooling mass flow to a high-pressure recirculation, which corresponds to at least one high pressure of the compressor mass flow to which the subcooling mass flow is supplied.
  • the expansion unit has a mass flow return for the compressor, with which a mass flow from one of the compressor outlet leading line to a line leading to the compressor input can be activated and controlled.
  • Such a mass flow recirculation has the advantage that it can be used to influence the mass flow through the subcooling unit by returning a mass flow of refrigerant, which is conveyed through the compressor, and thus complements the mass flow led through the subcooling unit and thereby through the subcooling unit guided mass flow can be reduced. It is particularly favorable if the mass flow return has a compressor bypass line and a control valve assigned to it, which is thus able to regulate or control the size of the mass flow flowing through the compressor bypass line.
  • control valve is controlled by a controller, the temperature differences between a temperature applied to the supercooling unit on the cooking pressure side and one after the
  • Expansion device present temperature and / or a
  • an advantageous solution provides that the expansion unit has a controller which, to stabilize the operation of the expansion unit, has a temperature of the refrigerant present on the high-pressure side before it enters the supercooling unit and
  • Temperature of the refrigerant emerging from the supercooling unit and present at the inlet pressure of the compressor stage determines that the control determines a temperature difference between these two temperatures and checks whether this is greater or less than a maximum difference, and in the event that this is greater than the maximum difference is activated and / or increased by the mass flow feedback.
  • the maximum difference is preferably in the range from 2 to 5 Kelvin.
  • the expansion unit has a controller which, in order to stabilize its operation, has a temperature of the refrigerant present on the high-pressure side after it has left the supercooling unit and a temperature of the supercooling pressure before it enters the supercooling unit expanded refrigerant determines that the controller determines a temperature difference between these two temperatures and checks whether this is less than or greater than a minimum difference, and in the event that it is less than a minimum difference, activates the mass flow through the mass flow feedback and / or enlarged.
  • the minimum difference is preferably in the range from 2 to
  • expansion unit to have a control which, in order to stabilize its operation, determines a pressure of the refrigerant present at the inlet pressure of the compressor stage, from this determines the evaporation temperature of the same, and also the temperature of the one from the subcooling unit rotating refrigerant present at the inlet pressure of the compressor stage, and from these temperatures a
  • Overheating difference is determined and, in the event that this overheating difference is less than a minimum overheating value, the mass flow feedback is activated and / or increased.
  • the minimum overheating value is in the range from 3 to 7 Kelvin.
  • the expansion unit can also be stabilized with regard to its operation in that the expansion unit has a controller which, in order to stabilize its operation, has a temperature of the refrigerant present on the high-pressure side before entering the supercooling unit and
  • Temperature of the refrigerant emerging from the supercooling unit and present at the inlet pressure of the compressor stage determines that the The controller determines a temperature difference between these two temperatures and checks whether this is greater or less than a maximum difference and, if this is greater than the maximum difference, generates and / or increases a bypass mass flow by activating the bypass line.
  • the expansion unit has a controller which, in order to stabilize its operation, determines a temperature of the refrigerant present on the high-pressure side after exiting the supercooling unit and a temperature of the refrigerant present before entry into the supercooling unit and at supercooling pressure. that the controller determines a temperature difference between these two temperatures and checks whether this is less than or greater than a minimum difference, and in the event that it is less than a minimum difference, generates and / or increases a bypass mass flow by activating the bypass line.
  • the expansion unit has a controller which, in order to stabilize the operation thereof, has a pressure on it
  • Superheat difference is smaller than a minimum value, generates a bypass mass flow by activating the bypass line and / or
  • the expansion unit has a controller which determines and opens an opening degree of the expansion member controlling the supercooling mass flow
  • the expansion unit has an electrically operating control which has at least one of the following variables, such as a temperature influenced by or corresponding to the ambient temperature, a temperature (Tamb) of the
  • an electrically operating control which has at least one of the following variables such as: an ambient temperature, a temperature of the expansion unit and / or the expander stage
  • the mass flow flowing to the expander stage and relevant for the inlet pressure of the expansion unit or the expansion compression unit is set exclusively via the control of the subcooling mass flow by means of the one controlled by the control
  • Compression of the supercooling mass flow can be used in the compressor stage, so that, at the same time, optimal expansion of the expanded mass flow takes place before it expands.
  • the expansion element includes an electrical one
  • One solution provides for the controller to control the ambient temperature and / or the temperature of the mass flow of the refrigerant
  • Another solution comprising the temperature of the mass flow of the refrigerant provides for the temperature of the mass flow of the refrigerant to be measured with a sensor before it enters the supercooling unit and before it enters the expander.
  • Another solution provides that the control system detects the ambient temperature by means of a sensor and either alone or, if necessary, in
  • control is an electronic control comprising a processor, which controls the expansion element electrically by means of a control program, since with a processor the various correlations between the measured temperature and that with the
  • Expansion device to be controlled supercooling mass flow can be realized in a simple manner.
  • a sensor connected to the control is provided in a connecting line between the subcooling unit and the compressor stage, by a
  • control program is in particular designed such that it either has an algorithm for determining the
  • Control of the expansion device includes or a stored
  • Correlation table which correlates the setting of the expansion element with the measured temperature of the mass flow supplied.
  • Various possibilities are conceivable with regard to the position of the branch for branching the supercooling mass flow from the total mass flow.
  • branch is arranged in front of an inlet of the supercooling unit on the high-pressure side.
  • a favorable solution provides that the branch is arranged between the subcooling unit and the expansion compression unit and branches off the subcooling mass flow from the total mass flow after the subcooling unit.
  • This solution also has the advantage that pulsations originating from the expansion compression unit are damped by the supply line leading away from the branch with the expansion element.
  • the supercooling unit can be designed differently.
  • One solution provides that the subcooling unit is designed as a heat exchanger unit and cools the mass flow of refrigerant flowing to the expander stage by the subcooling mass flow conducted in counterflow.
  • the subcooling unit is designed as a collecting container, in which a bath of liquid refrigerant of the subcooling mass flow is formed, which is used for the
  • Expander stage flowing mass flow of the refrigerant cools through the bath-guiding element, wherein a gas volume forms from the bath, from which the gaseous supercooling mass flow is removed.
  • This solution has the advantage that, on the one hand, the mass flow guided through the element is optimally subcooled and, on the other hand, the removal of the subcooling mass flow from the gas volume ensures that no liquid refrigerant is supplied to the compressor stage for compression.
  • the expander and the compressor stage could be coupled, for example, by a generator motor unit.
  • a particularly advantageous solution provides that the expander and the compressor stage of the expansion compression unit are mechanically functionally coupled.
  • this solution also has the advantage that the solution according to the invention, namely the control of the mass flow expanded by the expander, can be controlled in a simple manner via the supercooling mass flow, which is compressed by the compressor stage.
  • the expander stage and the compressor stage can be formed by suitable types of rotatingly driven machines.
  • a particularly advantageous solution provides that the expander stage and the compressor stage are formed by a free-piston machine in which at least one free-piston can move freely in a piston chamber.
  • the expansion compression unit is preferably designed such that it has two piston chambers, in each of which a free piston can be moved.
  • the free pistons can preferably be moved coupled to one another.
  • a first free piston in the respective piston chamber is a first one
  • Expansion chamber and a first compression chamber separate.
  • a second free piston in the respective piston chamber separates a second expansion chamber from a second compression chamber.
  • the two free pistons are arranged coaxially with one another in the piston chambers and are movable.
  • the first piston chamber is expediently from the second
  • Piston chamber separated by a separator An advantageous operation of the expansion compression unit can be realized if the two expansion chambers are arranged adjacent to the separating body in the piston chambers.
  • the two compression chambers are arranged on the sides of the respective free pistons opposite the expansion chambers.
  • the free pistons can work independently of each other.
  • the coupling element is designed such that it extends through the expansion chambers as far as the respective free piston.
  • the inflow of the refrigerant to the expansion chambers it is preferably provided that these can be controlled by a slide system.
  • Such a slide system is designed, for example, as an interchangeable slide, so that in a slide position the refrigerant flows into a
  • Expansion chamber flows and flows out of the other expansion chamber and in the other slide position the refrigerant flows into the other expansion chamber and flows out of the other expansion chamber.
  • the slide system can be controlled by a slide drive with which the two slide positions can be set.
  • a slide drive can be implemented by an electrical control which detects at least one position of the free pistons by means of at least one position sensor assigned to them.
  • an advantageous solution provides that the slide drive is caused by a pressure difference between an expander inlet and a
  • Expander output is controllable.
  • the slide drive is preferably designed as a double-acting actuating cylinder, the piston of which is acted upon on the one hand by the pressure at the expander inlet and on the other hand by the pressure at the expander outlet.
  • the slide drive can be controlled by a control slide, which controls the application of pressure to the piston at the expander inlet on the one hand and at the expander outlet on the other hand.
  • the control slide is preferably designed such that it detects the positions of the free pistons and moves accordingly.
  • control slide can be moved by the free pistons.
  • the expansion unit has one
  • control unit is also arranged on the device base.
  • control unit is also arranged on the device base.
  • a high-pressure inlet connection and an expansion pressure outlet connection are arranged on the device base.
  • a high-pressure outlet connection is arranged over the device base, via which the compressed supercooling mass flow flows out when the expansion unit is installed.
  • a further advantageous solution provides that heat exchanger connection units are provided on the base of the device, by means of which several heat exchangers on the high-pressure side can be connected.
  • each of the heat exchanger connection units is designed such that it each has a three-way valve and a bypass for the respective heat exchanger, so that the three-way valve enables the flow through the respective heat exchanger to be controlled.
  • At least one of the heat exchanger connection units is connected to a heat exchanger on the high-pressure side that emits heat to the ambient air.
  • Phase separator is arranged, the gas phase of which is fed from a suction pressure line to the refrigerant compressor.
  • Such a phase separator has the advantage that it prevents liquid refrigerant from being supplied to the refrigerant compressor for compression.
  • cooling stage has at least one expansion element, so that it is possible to use it to determine the pressure desired in the cooling stage.
  • the invention relates to an expansion unit, in particular for a refrigerant circuit according to one or more of the preceding features, comprising an activatable and deactivatable expansion compression unit having an expander stage and a compressor stage, which expansion mass flow supplied from a high pressure input connection to a high pressure input connection, starting from high pressure to an expansion pressure
  • Expansion units of this type are also known from the prior art, with these expansion units also having the problem of operating them as optimally as possible.
  • the expansion compression unit is assigned an operational adjustment unit which comprises a bypass line which can be activated and deactivated bypassing the expansion compression unit, and that the operational adjustment unit has the bypass line in the event of a suboptimal operating state of the expansion unit converted from an inactive to an active state, in which this one by diverting the high-pressure refrigerant
  • the advantage of the solution according to the invention can also be seen in the fact that the problem is solved by the operating adaptation unit according to the invention that, in the event of unstable operation of the expansion unit, in particular the expansion compression unit, its function is restricted with regard to the expansion to be carried out, so that in one Adequate cooling capacity can no longer be provided in the refrigerant circuit.
  • the operating adaptation unit according to the invention solves this problem in that it is able to generate a diversion mass flow and to supply it to the expansion pressure output connection of the expansion unit.
  • the expansion unit has a supercooling unit for subcooling at least the expansion mass flow of the refrigerant supplied to the expansion unit, that the expansion unit comprises the expansion compression unit the
  • Expander stage and the compressor stage has a branch which branches off a subcooling mass flow from the total mass flow supplied to the expansion unit and which is connected to a feed line which leads the subcooling mass flow to an input of the subcooling unit such that the expansion unit has an expansion element provided in the feed line has, which expands the supercooling mass flow to a supercooling pressure, and that the expansion unit a
  • subcooling mass flow of the compressor stage which in turn compresses the subcooling mass flow to a high pressure return, which corresponds in particular to at least one high pressure of a compressor mass flow to which the subcooling mass flow is supplied.
  • expansion unit allows it to be operated in a highly energy-efficient manner.
  • the expansion unit according to the invention thus creates the possibility of deactivating the operating adaptation unit and activating the expansion compression unit or deactivating the expansion compression unit and activating the operating adaptation unit or operating both the expansion compression unit and the operating adaptation unit activated in parallel.
  • An advantageous solution thus provides that the operating adaptation unit is activated in such a way that the operating adaptation unit is activated and the expansion compression unit is activated.
  • Another possibility provides that the operating adaptation unit is controlled in such a way that the expansion compression unit is deactivated after the bypass line has been activated.
  • Operational adaptation unit takes place so that after activating the
  • Bypass line a deactivation of the expansion compression unit takes place with a delay, so that parallel operation of the operating adaptation unit and the expansion compression unit is provided for a certain period of time, during which the operation of the expansion unit can be stabilized, but that if the instabilities continue to occur during operation of the expansion unit, the expansion compression unit is deactivated he follows.
  • Ambient temperature influenced temperature recorded.
  • a particularly simple solution provides that the operating adaptation unit is controlled in such a way that the operating adaptation unit is at a detected temperature that is above a temperature threshold required for a stable operating state of the expansion unit
  • Operating adaptation unit is carried out in such a way that the operating adaptation unit activates the bypass line at a detected temperature which is below a temperature threshold necessary for a stable operating state of the expansion unit, that is to say in this case the operating adaptation unit is active, in which case the operating adaptation unit is parallel to active expansion compression unit can be operated or, if further major instabilities occur in the area of the expansion unit, the expansion compression unit can be deactivated.
  • the operating adaptation unit is controlled in such a way that the operating adaptation unit is either activated or deactivated at intervals or a mass flow through the bypass line at a detected temperature which is below a lower temperature threshold, which is lower than the temperature threshold for activating the bypass line controls by means of an expansion device.
  • Control bypass either by activating and deactivating it at intervals or by an expansion device.
  • An advantageous solution thus provides for the operating adaptation unit to be activated based on an expansion fault in the expansion unit.
  • Such expansion control of the expansion unit can be detected either by strong pressure fluctuations, for example the high pressure, or by temperature fluctuations, for example, the temperatures at the subcooling unit.
  • Operating adaptation unit detects the high pressure of the total mass flow entering the high pressure inlet connection or of the expansion mass flow before it enters the expander stage.
  • Operating adaptation unit based on a pressure difference between the high pressure of the total mass flow or the expansion mass flow before it enters the expander and the expansion pressure outlet connection.
  • a further possibility for controlling the operating adaptation unit provides that this takes place based on the high pressure of the total mass flow or of the expansion mass flow before it enters the expander stage with regard to an absolute value.
  • Another solution provides that the operating adaptation unit is activated based on a comparison of the high pressure of the
  • Total mass flow or the expansion mass flow occurs before it enters the expander stage with a predetermined reference high pressure.
  • bypass line can be activated and deactivated by means of a switching valve.
  • Such a switching valve can preferably be designed such that, when activated, it allows the bypass mass flow to pass without pressure loss.
  • At least one expansion element is functionally assigned to the bypass line, which is effective when the bypass line is activated and which opens up the possibility of controlling the bypass mass flow.
  • the expansion unit has at least one
  • Has shutdown element for deactivating the expansion compression unit has shutdown element for deactivating the expansion compression unit.
  • the switch-off element is preferably arranged either in front of an expander inlet or after an expander outlet.
  • Another solution provides that a switching element is provided in the bypass line of the operating adaptation unit, which creates a direct or indirect connection between the expansion element for generating the supercooling mass flow of the expansion unit and an expansion pressure outlet connection of the expansion unit.
  • bypass line is arranged in such a way that the expansion element can be used to generate the subcooling mass flow in order to activate the bypass mass flow, in which case no subcooling mass flow preferably occurs, since it is expedient in this case the expansion compression unit is deactivated.
  • the switching element can either by controlling the
  • Expansion unit can be controlled.
  • the switching element is designed as a switching valve.
  • Compressor input leading line is controllable.
  • the mass flow return has a compressor bypass line and a control valve assigned to it, for example an expansion device, in order to be able to control or regulate the mass flow through the mass flow return.
  • an advantageous solution provides that the expansion unit has a controller which, to stabilize the operation of the expansion unit, has a temperature of the refrigerant present on the high-pressure side before it enters the supercooling unit and
  • Temperature of the refrigerant emerging from the supercooling unit and present at the inlet pressure of the compressor stage determines that the control determines a temperature difference between these two temperatures and checks whether this is greater or less than a maximum difference, and in the event that this is greater than the maximum difference is activated and / or increased by the mass flow feedback.
  • the expansion unit has a controller which, in order to stabilize its operation, has a temperature of the refrigerant present on the high-pressure side after exiting the supercooling unit and a temperature of the refrigerant present before entering the supercooling unit and expanded to supercooling pressure determines that the controller determines a temperature difference between these two temperatures and checks whether this is less than or greater than a minimum difference, and in the event that it is less than a minimum difference, activates the mass flow through the mass flow feedback and / or increased.
  • the minimum difference is preferably in the range from 2 to
  • an alternative or additional, further advantageous solution provides for the expansion unit to have a control which, in order to stabilize its operation, determines a pressure of the refrigerant present at the inlet pressure of the compressor stage, from this determines the evaporation temperature of the same, and also the temperature of the one from the subcooling unit unscrewing refrigerant present at the inlet pressure of the compressor stage, and from these temperatures a superheat difference is determined and in the event that this superheat difference is less than a minimum superheat value, the mass flow feedback is activated and / or increased.
  • the minimum overheating value is in the range from 3 to 7 Kelvin.
  • the expansion unit has a controller which determines and opens an opening degree of the expansion member controlling the supercooling mass flow
  • the expansion unit can also be stabilized with regard to its operation in that the expansion unit has a controller which, in order to stabilize its operation, has a temperature of the refrigerant present on the high-pressure side before entering the supercooling unit and
  • Temperature of the refrigerant emerging from the supercooling unit and present at the inlet pressure of the compressor stage determines that the control determines a temperature difference between these two temperatures and checks whether this is greater or less than a maximum difference and in the event that this is greater than the maximum difference generates and / or increases a bypass mass flow by activating the bypass line.
  • the expansion unit has a controller which, in order to stabilize its operation, determines a temperature of the refrigerant present on the high-pressure side after exiting the supercooling unit and a temperature of the refrigerant present before entry into the supercooling unit and at supercooling pressure. that the controller determines a temperature difference between these two temperatures and checks whether this is less than or greater than a minimum difference, and in the event that it is less than a minimum difference, generates and / or increases a bypass mass flow by activating the bypass line.
  • the expansion unit has a controller which, in order to stabilize the operation thereof, has a pressure on it
  • Input pressure of the compressor stage present refrigerant determined, from it the vaporization temperature of the same, and also the Determines the temperature of the refrigerant emerging from the supercooling unit at the inlet pressure of the compressor stage and determines an overheating difference from these temperatures and, if this overheating difference is less than a minimum value, generates a bypass line flow by activating the bypass line and / or
  • the expansion unit has a controller which determines and opens an opening degree of the expansion member controlling the supercooling mass flow
  • the expansion unit has an electrically operating control, which has at least one of the following variables, such as a temperature influenced or corresponding to an ambient temperature, a temperature of the mass flow of the refrigerant supplied to the expansion unit and / or the expander stage, a high pressure of the total mass flow or of the expansion mass flow upstream of the expander stage and in accordance with this temperature and / or possibly this high pressure of the total mass flow or
  • the task mentioned at the outset is also achieved by an expansion unit, in particular comprising the features known from the prior art, in that the expansion unit has an electrically operating controller which has at least one of the following variables, such as: one from an ambient temperature influenced or this corresponding temperature (T amb ), a temperature of the mass flow of the refrigerant supplied to the expansion unit and / or the expander stage, an input pressure of the compressor stage, and
  • control detects the ambient temperature and / or the temperature of the mass flow of the refrigerant in front of an input of the supercooling unit and / or in front of an expander input by means of a sensor.
  • control is an electronic control comprising a processor, which controls the respective components electrically by means of a control program.
  • Heat exchanger is formed and cools the mass flow of the refrigerant flowing to the expander stage by the supercooling mass flow conducted in counterflow. It is also expediently provided that the branch is arranged in front of an inlet of the supercooling unit on the high-pressure side.
  • the branch is arranged between the subcooling unit and the expansion compression unit and branches off the subcooling mass flow from the total mass flow after the subcooling unit.
  • expander stage and / or the compressor stage of the expansion compression unit are mechanically functionally coupled, in particular are rigidly coupled to one another.
  • the expander stage and the compressor stage are formed by a free-piston machine in which at least one free-piston is freely movable in a piston chamber.
  • the expansion compression unit has two piston chambers, in each of which a free piston can be moved.
  • the free pistons can preferably be moved coupled to one another.
  • a first free piston in the respective piston chamber is a first one
  • Expansion chamber and a first compression chamber separate.
  • a second free piston in the respective piston chamber separates a second expansion chamber from a second compression chamber.
  • the two free pistons are arranged coaxially with one another in the piston chambers and are movable.
  • the first piston chamber is expediently separated from the second piston chamber by a separating body.
  • An advantageous operation of the expansion compression unit can be realized if the two expansion chambers are arranged adjacent to the separating body in the piston chambers.
  • the two compression chambers are arranged on the sides of the respective free pistons opposite the expansion chambers.
  • the free pistons can work independently of each other.
  • the coupling element is designed such that it extends through the expansion chambers as far as the respective free piston.
  • a slide system is designed, for example, as an interchangeable slide, so that in a slide position the refrigerant flows into a
  • Expansion chamber flows and flows out of the other expansion chamber and in the other slide position the refrigerant flows into the other expansion chamber and flows out of the other expansion chamber.
  • the slide system can be controlled by a slide drive with which the two slide positions can be set.
  • Such a slide drive can be implemented by an electrical control which detects at least one position of the free pistons by means of at least one position sensor assigned to them.
  • an advantageous solution provides that the slide drive is caused by a pressure difference between an expander inlet and a
  • Expander output is controllable.
  • the slide drive is preferably designed as a double-acting actuating cylinder, the piston of which is acted upon on the one hand by the pressure at the expander inlet and on the other hand by the pressure at the expander outlet.
  • the slide drive can be controlled by a control slide, which controls the application of pressure to the piston at the expander inlet on the one hand and at the expander outlet on the other hand.
  • the control slide is preferably designed such that it detects the positions of the free pistons and moves accordingly.
  • control slide can be moved by the free pistons.
  • the expansion unit has a device base on which the supercooling unit and the expansion compression unit are arranged.
  • control unit is also arranged on the device base.
  • a high-pressure outlet connection is arranged over the device base, via which the compressed supercooling mass flow flows out when the expansion unit is installed.
  • a further advantageous solution provides that heat exchanger connection units are provided on the device base, with which several high-pressure side heat exchangers can be connected.
  • At least one of the heat exchanger connection units is connected to a heat exchanger on the high-pressure side that emits heat to the ambient air.
  • FIG. 1 shows a schematic illustration of a first exemplary embodiment of a refrigerant circuit according to the invention with a first exemplary embodiment of an expansion unit according to the invention with a first embodiment of an operating adaptation unit;
  • FIG. 2 shows an enlarged schematic illustration of the first exemplary embodiment of an expansion unit according to the invention with the first embodiment of an operating adaptation unit;
  • FIG. 3 shows a schematic illustration of a first exemplary embodiment of an expansion unit according to the invention
  • Fig. 4 is a schematic representation similar to Fig. 3 of a second
  • FIG. 5 shows a schematic illustration of a second exemplary embodiment of the refrigerant circuit according to the invention with a second embodiment of an operating adaptation unit
  • Fig. 6 is a schematic representation of the first embodiment of the
  • Fig. 7 is a schematic representation of the first embodiment of the
  • Fig. 8 is a schematic representation of the first embodiment of the
  • Expansion unit with a fifth embodiment of an operational adjustment unit shows a schematic illustration of a second exemplary embodiment of an expansion unit according to the invention with a sixth embodiment of an operating adaptation unit;
  • FIG. 10 shows a schematic illustration of a third exemplary embodiment of an expansion compression unit according to the invention with the sixth embodiment of the operating adaptation unit;
  • Fig. 11 is a schematic representation of the first embodiment of the
  • FIG. 12 shows a schematic illustration of the first exemplary embodiment of an expansion unit with the seventh embodiment of an operating adaptation unit in a second position of the 3/2-way valve;
  • FIG. 13 shows a schematic illustration of a third exemplary embodiment of an expansion unit
  • FIG. 14 shows a schematic illustration of a third exemplary embodiment of the expansion unit with a modified compressor bypass
  • Fig. 15 is a schematic representation of the third embodiment of the
  • Expansion unit with a second embodiment of the operating adaptation unit integrated into the expansion system
  • FIG. 16 shows a schematic illustration of a third exemplary embodiment of a refrigerant circuit according to the invention.
  • 17 shows a schematic illustration of a fourth exemplary embodiment of a refrigerant circuit according to the invention
  • 18 shows a schematic illustration of a fifth exemplary embodiment of a refrigerant circuit according to the invention
  • FIGS. 1 to 18 shows a flowchart relating to the activation or deactivation of the expansion units with the expansion compression units and the operational adaptation units in the exemplary embodiments according to FIGS. 1 to 18;
  • Fig. 20 is a diagram showing the activation and / or deactivation of the
  • FIG. 21 shows a schematic illustration of the third exemplary embodiment of the refrigerant circuit according to the invention corresponding to FIG. 16 with an operating adaptation unit in which a bypass mass flow cannot be regulated or controlled but can only be activated or deactivated;
  • FIG. 22 shows a schematic illustration of a fourth exemplary embodiment of a refrigerant circuit according to the invention corresponding to FIG. 17 with an operating adaptation unit in which the bypass mass flow cannot be controlled or regulated but can only be activated or deactivated;
  • FIG. 23 shows a schematic illustration of the fifth exemplary embodiment of a refrigerant circuit according to the invention with an operating adaptation unit in which the mass flow cannot be controlled or regulated but can only be activated or deactivated and
  • Fig. 24 is a flowchart for the activation or deactivation of the
  • 25 is a diagram which schematically shows the activation and / or
  • a first exemplary embodiment of a refrigeration system according to the invention shown in FIG. 1, comprises a first exemplary embodiment of a refrigerant circuit, designated as a whole by 10, in which a refrigerant compressor unit, designated as a whole by 12, is arranged, which for example comprises at least one refrigerant compressor.
  • the refrigerant compressor unit 12 has a suction port 14 and a pressure port 16, with refrigerant compressed to high pressure PHI usually being present at the pressure port 16.
  • refrigerant compressed to high pressure is understood to mean that the refrigerant has the highest pressure present in the refrigerant circuit.
  • a high-pressure line 18 leads from the pressure connection 16 a compressor mass flow V compressed by the refrigerant compressor unit 12 to high pressure PHI to an inlet 24 of a heat-emitting heat exchanger on the high-pressure side, designated as a whole by 22, which
  • leading high-pressure line 28 is fed to a high-pressure regulating expansion unit 32, designated as a whole by 32, which has a high-pressure inlet connection 34 connected to the high-pressure line 28, an expansion pressure outlet connection 36 and a high-pressure outlet connection 38.
  • the expansion pressure outlet connection 36 which is at an expansion pressure PE, is connected to an expansion line 42 which, in the simplest exemplary embodiment shown in FIG. 1, leads to a cooling stage 62 which, in the simplest case, has a heat exchanger which absorbs heat from this medium for cooling an external medium 64 has.
  • the heat-absorbing heat exchanger 64 is at the expansion pressure PE, so that no separate expansion valve is connected upstream of this heat exchanger 64.
  • the heat-absorbing heat exchanger 64 is followed by a phase separator 72, which is arranged in a suction pressure line 74, which leads from the cooling stage 62 to the suction port 14 of the refrigerant compressor unit 12 and prevents liquid refrigerant from the refrigerant compressor unit 12 at the suction port 14 is sucked in.
  • Expansion pressure PE is the expansion pressure mass flow EPM through the expansion line 42 to the cooling stage 62 and from the cooling stage 62 in turn via the suction pressure line 74 to the refrigerant compressor unit 12.
  • the expansion pressure mass flow EPM does not correspond to the total mass flow, but the expansion unit 32 divides the total mass flow G into an expansion mass flow EM and a subcooling mass flow UM, which is generated by the expansion unit 32 at the high pressure outlet connection 38 at a return pressure PR as a subcooling return mass flow URM is returned to a return line 78 and is fed from the latter to the compressor mass flow V before it enters the heat-emitting high-pressure side heat exchanger 22.
  • the refrigerant circuits 10 according to the invention are all preferably for carbon dioxide, that is to say CO2, or
  • Refrigerant to a temperature that corresponds to the isotherms running above the thaw and boiling line or saturation curve, so that there is no liquefaction of the refrigerant.
  • Condensation of the refrigerant takes place at a temperature that passes through the refrigerant's thawing and boiling line or saturation curve
  • the first exemplary embodiment of the expansion unit 32 designed according to the invention in the first exemplary embodiment of the refrigerant circuit comprises, as shown enlarged in FIG. 2, an expansion system 30 which has a device base, designated as a whole by 82, on which the high-pressure inlet connection 34 of the expansion pressure-outlet connection 36 and the high-pressure outlet connection 38 are arranged. Furthermore, in the expansion system 30, an expansion compression unit 84 is connected to the device base 82, which comprises an expander stage 86 and a compressor stage 88, which are integrated in the expansion compression unit 84 and are rigidly coupled to one another.
  • the expansion compression unit 84 comprises an expander inlet 92 and an expander outlet 94, which is connected to the expansion pressure outlet connection 36, as well as a compressor inlet 96 and a compressor outlet 98, which in turn is connected to the high pressure outlet connection 38.
  • a subcooling unit 102 is arranged on the device base 82, which in the first exemplary embodiment is designed as a countercurrent heat exchanger and has an input 104 and an output 106 for the mass flow to be cooled, in particular in this case the total mass flow G, and an input 112 and an output 114 for the subcooling mass flow UM which is conducted through the heat exchanger as a countercurrent.
  • the supercooling mass flow UM is branched off at a branch 116 from the total mass flow G emerging and supercooled at the output 106 of the supercooling unit 102, so that an expansion mass flow EM is led from the branch 116 through a feed line to the expander inlet 92 and the supercooling mass flow UM through Shut-off device 124 and one with an actuator 123
  • the driven expansion element 122 is guided in the supply line 126, in which the supercooling mass flow UM is expanded to a pressure PU, and is then fed to the input 112 of the subcooling unit 102, the subcooling mass flow UM in the subcooling unit 102 in counterflow from the input 104 to the output 106 flowing total mass flow G subcooled and from the outlet 114 by means of a
  • Connection line 128 is supplied to the compressor input 96.
  • the mechanical energy released in the expander stage 86 by expansion of the expansion mass flow EM is fed in the expansion compression unit 84 through a mechanical functional coupling directly to the compressor stage 88 and leads to a compression of the supercooling mass flow UM by one at the outlet 114 of the supercooling - Unit 102 present input pressure EP of the compressor stage 88 to a return high pressure PR, which corresponds to or higher than the pressure level PHI in the high pressure line 18, so that the supercooling return mass flow URM from the high pressure output connection 38 via a high pressure return line 78 to the compressor mass flow V is supplied can.
  • a controller 132 is also provided in the expansion system 30, which on the one hand detects, for example with a sensor 134, which is in particular a pressure and / or temperature sensor, the temperature of the mass flow of the refrigerant before its expansion in the expansion stage 86 and, for example, in accordance with this temperature of the actuator 123 controls the expansion element 122.
  • a sensor 134 which is in particular a pressure and / or temperature sensor, the temperature of the mass flow of the refrigerant before its expansion in the expansion stage 86 and, for example, in accordance with this temperature of the actuator 123 controls the expansion element 122.
  • sensor 134 is arranged, for example, between branch 116 and expander 86 as sensor 134i.
  • the controller is also a pressure and / or temperature sensor 135
  • the senor 134 can also be used as a sensor 1342 between the high-pressure input connection 34 and the supercooling unit 102.
  • the sensor 134 as the sensor 134 3, measures the ambient temperature, which in particular decisively influences the temperature of the total mass flow G of the refrigerant at the outlet 26 of the heat exchanger 22 through the ambient air flowing through the heat exchanger 22.
  • the controller 132 can, for example, work autonomously, so that the controller 132 is part of the expansion system 30 which is installed as an independent unit in the refrigerant circuit.
  • controller 132 is coupled to an external controller 138 which, as shown in FIG. 1, as an alternative or in addition to the sensors 134, the temperature of the total mass flow G in the high-pressure section 28 and / or the temperature or Pressure in the refrigerant compressor 12 is detected in order to control the actuator 123 directly or indirectly or by means of the control 132.
  • the expansion element 122 serves to control the supercooling mass flow UM, and thereby the high pressure PH2 at the high pressure input connection 34 and thus also the high pressure PH2 in the high pressure line 28 in accordance with one of the controls 132 and / or the external controller 138, in particular one in this relationship, stored as a file or algorithm, as a function of the respectively measured temperature of the refrigerant and thus as a function of the possibilities for cooling the refrigerant on the high pressure PH2, for example as a function of that for cooling in the heat exchanger 22
  • the controller 132 and / or the external controller 138 comprise, for example, a processor and a memory in which an algorithm or a
  • Correlation tables are stored, by means of which a correlation between the settings of the expansion element 122 and the measured ones
  • Temperatures or pressures is stored, so that the settings of the expansion element 122, made by the actuator 123 controlled by the controller 132, lead to the high-pressure inlet connection 34 and / or the inlet 104 of the supercooling unit 102 and / or the expander inlet 92 sets the high pressure PH2 corresponding to the temperature.
  • the subcooling mass flow UM usually comprises approximately 15% to 35% of the total mass flow G, so that the expansion mass flow EM comprises approximately 85% to 65% of the total mass flow G.
  • the regulation of the high pressure PH2 takes place in such a way that in the subcooling unit 102 the temperature of the total mass flow G on the hot side, ie at the inlet 104, is only a few Kelvin, for example less than 4 Kelvin, better still less than 3 Kelvin, in particular one up to two Kelvin, above the temperature of the subcooling mass flow UM at the outlet 114 of the subcooling unit 102, in order to substantially completely evaporate the refrigerant in the subcooling mass flow U.
  • a sensor 135 connected to the controller 132 is provided in particular in the connecting line 128.
  • the expansion compression unit designated as a whole by 84, is designed as a free-piston machine, which has a cylinder housing 142 in which two piston chambers 144 and 146, which are separate from one another, are arranged, with a movable free piston in each piston chamber 152, 154 is arranged.
  • the free pistons 152 and 154 divide the respective piston chambers 144 and 146 into expansion chambers 162 and 164 and compression chambers 166 and 168.
  • the free pistons 152 and 154 are preferably mechanically coupled to one another, in such a way that, at the maximum volume of the first expansion chamber 162, the first piston 152 is positioned such that the first compression chamber 166 has a minimum volume and at the same time the second free chamber piston 154 is such that its expansion chamber 164 has a minimum volume, while the compression chamber 168 has the maximum volume or vice versa.
  • an increase in volume of the first expansion chamber 162 when it is acted upon by the high pressure at the expander inlet 92, leads to a compression of refrigerant of the supercooling mass flow U in the first compression chamber 166, at the same time to an expulsion of the refrigerant in the second compression chamber 168 in the direction of the expander outlet 94 and for drawing in refrigerant in the second compression chamber 168 via the compressor inlet 96.
  • the first free piston 152 and the second free piston 154 are preferably arranged coaxially to one another and move in piston chambers 144 and 146 which are likewise arranged coaxially to one another and are separated from one another by a separating body 148, the separating body 148 being sealed by a coupling element 172 which penetrates the
  • the coupling element 172 can be designed as a coupling rod which penetrates the separating body 158 and which moves with the free pistons 152, 154 and which is in free contact with the free pistons 152 and 154, that is to say is not firmly connected to them.
  • the pressure in this expansion chamber 162 or 164 acts on the respective free piston 152 or 154 and at the same time a pressure which is higher in the respective compression chamber 168 or 166 of the other free piston 154 or 152 acts
  • a pressure which is higher than that at the expander inlet 92 can be generated in the compression chamber 166 or 168 acted upon by the free piston 152 or 154 applied high pressure, so that the supercooling mass flow U can be compressed to a pressure present at the compressor outlet 98 which corresponds at least to the high pressure PHI at the inlet 24 of the heat-emitting heat exchanger or the pressure in the high pressure line 18, although the high pressure PH2, the expander inlet to Is available due to pressure losses in the heat exchanger 22 is slightly smaller than the high pressure PHI.
  • Compressor inlet 96 are from compressor inlet 96
  • Supply lines 182 are provided which lead to the inlet valves 184 and 186 assigned to the compression chambers 166 and 168, and the compressor outlet 98 is also connected to a pressure line 192 which leads from the outlet valves 194 and 196 assigned to the compression chambers 166 and 168 to the compressor outlet 98.
  • the slide system 202 comprises a controller 203, which detects the positions of the free pistons 152 and 154 by means of position sensors 204 and 206 and controls an exchangeable slide, designated as a whole by 208, which has two slide positions and one in the slide position by means of an electric drive 207 Expander inlet 92 with the expansion chamber 162 and the expander outlet 94 with the
  • Expansion chamber 164 and in the other slide position connects the expander inlet to the expansion chamber 164 and the expander outlet 94 to the expansion chamber 162.
  • a pressure control of the change-over slide 208 is provided in a slide system 202 ', the drive 207' having a pressure-driven cylinder with a piston 205, which, controlled by an auxiliary slide 209, alternately on the one hand with the pressure at the expander inlet 92 and, on the other hand, the pressure at the expander outlet 94 or vice versa is applied, the auxiliary slide 209 also being designed as a change-over slide and its slide positions being achieved by mechanical detection of the positions of the free pistons 152 and 154 in their end positions facing the separating body 148.
  • the expansion compression unit 84 is configured as a free-piston machine, malfunctions, for example suboptimal, in particular unstable operating states, can occur, so that no expansion pressure mass flow EPM or a sufficiently large one
  • Expansion pressure mass flow EPM would be available for the cooling unit 62, cooling capacity would no longer be available at the cooling unit 62, so that the refrigerant circuit 10 would no longer be functional.
  • the refrigerant circuit 10 has a
  • Operation adaptation unit 230 which prevents this case.
  • a first embodiment of an operating adaptation unit 230 provided in the expansion system 30 includes, for example, an additional one
  • Expansion element 232 which is arranged in a bypass line 234, which in turn is the expander stage 86, in particular between the latter
  • Expander inlet 92 and expander outlet 94 connected in parallel, and is designed as a controllable expansion element which can be controlled by the controller 132 or 138, which detects, for example, the high pressure PH2 and then opens in a controlled manner when a predeterminable high pressure level is exceeded and acts as an expansion element in the bypass line 234 , so that through the expansion element 232 in the bypass line 234
  • Redirection mass flow ULM is fed to the expansion line 42, which can then absorb heat in the cooling unit 62, so that the refrigerant circuit 10 can continue to run stably (FIGS. 1 and 2).
  • the bypass mass flow ULM is controlled so that the
  • the expansion compression unit 84 is activated by means of a switching valve 236
  • a mass flow recirculation 240 assigned to the compressor 88 is provided, which comprises a compressor bypass line 242, which connects the line 128 leading to the compressor inlet 96 with one of the
  • Compressor outlet 98 connects leading line and in which a controlled control valve 244 is provided, with which a
  • Returned mass flow flowing through compressor input 96 is controllable in order to reduce the supercooling mass flow UM.
  • the control valve 244 can be controlled in a wide variety of ways.
  • the controller 132, 138 to stabilize the operation of the expansion unit 32 has a temperature of the refrigerant present on the high-pressure side before it enters the supercooling unit 102 and a temperature of that from the subcooling unit
  • escaping refrigerant present at the inlet pressure of the compressor stage determines that the controller 132, 138 determines a temperature difference between these temperatures and checks whether this is greater or less than a maximum difference, and if this is greater than the maximum difference, the Mass flow activated and / or increased by the mass flow return.
  • the maximum difference is preferably in the range from two to five Kelvin.
  • a variant of the control of the control valve 244 provides that the
  • Temperature difference between these two temperatures determines and checks whether this is smaller or larger than a minimum difference, and in the event that it is smaller than the minimum difference, the mass flow is activated and / or increased by the mass flow feedback.
  • control 132, 138 determines a pressure of the refrigerant present at the inlet pressure EP of the compressor stage 88 to stabilize the operation of the expansion unit, determines the evaporation temperature of the same, and also the temperature of the refrigerant Subcooling unit 102 emerging refrigerant present at the input pressure EP of the compressor stage 88 is determined and from these temperatures a superheat difference is determined and, in the event that this superheat difference is less than a maximum superheat value, the mass flow feedback is activated and / or increased.
  • the maximum overheating value is preferably in the range from 3 to 7 Kelvin.
  • control valve 244 Another possibility for controlling the control valve 244 provides that the controller 132, 138 determines an opening degree of the expansion member 122 for the supercooling mass flow and controls the control valve 244 in accordance with the opening degree of the expansion member.
  • a further advantageous solution thus provides that the controller 132, 138 to stabilize the operation of the expansion unit 32 has a temperature of the refrigerant present on the high-pressure side before entering the supercooling unit 102 and a temperature of the refrigerant emerging from the supercooling unit 102 and present at the input pressure EP of the compressor stage 88 Refrigerant determines that the controller determines a temperature difference between these two temperatures and checks whether this is greater or less than a maximum difference, and in the event that it is greater than the maximum difference, by activating the bypass line 234 a bypass mass flow ULM generated and / or enlarged.
  • the bypass mass flow ULM is preferably controlled by the expansion element 232 functionally assigned to the bypass line 234.
  • a further advantageous solution provides that the controller 132, 138 determines a temperature of the refrigerant present on the high-pressure side after exiting the supercooling unit 102 and a temperature of the refrigerant present before the entry into the supercooling unit 102 and present at subcooling pressure PU in order to stabilize the operation of the expansion unit 32 that the controller 132, 138 determines a temperature difference between these two temperatures and checks whether this is less than or greater than a minimum difference, and in the event that it is less than the minimum difference, by activating the bypass line 234 a bypass mass flow ULM creates and / or enlarges.
  • the der is preferably activated
  • Bypass line functionally assigned expansion element. Another inexpensive solution provides that the controller 132, 138 determines the pressure of the refrigerant present at the input pressure EP of the compressor stage 88 to stabilize the operation of the expansion unit 32, determines the evaporation temperature thereof, and also the temperature of the exiting from the supercooling unit 102, on
  • Input pressure EP of the compressor stage 88 present refrigerant determined and determined from these temperatures a superheat difference and in the event that this superheat difference is less than a minimum value, by
  • bypass line 234 Activation of the bypass line 234 generates and / or increases a bypass mass flow ULM.
  • the der is preferably activated
  • Bypass line 234 functionally associated expansion element 232.
  • Another inexpensive solution for stabilizing the operation of the expansion unit provides that the controller 132, 138 determines an opening degree of the expansion element 122 generating the supercooling mass flow UM and, according to the degree of opening of this expansion element 122, the opening degree
  • bypass line 234 is activated and a bypass mass flow ULM is generated and / or increased, preferably with the expansion element 232 functionally assigned to the bypass line 234 being activated in accordance with the degree of opening of the expansion member 122.
  • a pulsation damper 260 is preferably connected to parts of the refrigerant circuit 10 adjoining the expander stage 86, for example to the expansion line 42, which comprises a damper housing 262 enclosing a damper chamber 264, in which at least one of the a bubble 266 from a subcritical operating state
  • the bubble 264 made of gaseous refrigerant thus makes it possible to dampen pulsations in the expansion pressure mass flow EPM, which also affect the bath 268 of the refrigerant.
  • the damper housing 262 is preferably provided in the region of the region surrounding the bladder 266 with a heater 274 which is provided via a heat transport circuit 276 supplies heat from return line 78 to damper housing 262 to maintain bladder 266 of vaporous refrigerant.
  • the operating adaptation unit 230 is not part of the expansion system 30, as described in connection with the first exemplary embodiment of the refrigerant circuit 10 according to the invention, but rather a unit which is independent of the expansion system 30, the expansion element 232 in FIG
  • Bypass line 234 ' is arranged, which in this case connects the high-pressure line 28 to the expansion line 42 and is thus connected in parallel to the entire expansion unit 32 (FIG. 5).
  • the expansion element 232 is activated, for example, by the controller 138 in accordance with the high pressure PH2 as in the first case
  • the first exemplary embodiment of the expansion unit 30 is assigned a third embodiment of an operating adaptation unit 230 ′′ which is designed such that the controllable expansion element 232 is arranged in a bypass line 234 ′′ (FIG.
  • the compressor stage 88 is also out of operation, so that no supercooling return mass flow URM flows to the high-pressure line 18 via the high-pressure outlet connection 38 and the return line 78.
  • the expansion element 232 and the shut-off element 236, it is necessary to actively control the expansion element 232 and the shut-off element 236, for example by means of an operating adaptation controller 238, which uses a sensor 246 to detect the high pressure PH2 present in the refrigerant circuit 10 before the expander stage 86, for example the high pressure between the outlet 106 of the lower cooling unit 102 and the expander inlet 92 detected (Fig. 6).
  • an operating adaptation controller 238 uses a sensor 246 to detect the high pressure PH2 present in the refrigerant circuit 10 before the expander stage 86, for example the high pressure between the outlet 106 of the lower cooling unit 102 and the expander inlet 92 detected (Fig. 6).
  • a modified mass flow return 240 ′ is provided, the compressor bypass line 242 ′ connecting the compressor outlet 98 to the inlet 112 of the supercooling unit 102, which is at a pressure existing after the expansion element 122.
  • controllable valve 244 ' is actuated by the controller 132, which detects the pressure difference mentioned in the same way as in the first exemplary embodiment.
  • Embodiment can be referenced.
  • shut-off element 236 is not arranged in front of the expander inlet 92, but immediately after the expander outlet 94, and the bypass line 234 ′ ′′ is thus the expander stage 86 with the shut-off element 236 , which is arranged following the expander output 94, connected in parallel.
  • the operating adaptation control 238 is provided on the one hand for controlling the expansion element 232 and the shut-off element 236.
  • the operating adaptation unit 230 "" comprises the shut-off element 237 and the shut-off element 236.
  • the shut-off element 236 arranged in front of the expander inlet 92 to by interrupting the in the expander 86
  • Expansion member 122 enters, and connects the expansion pressure outlet port 36 together.
  • Shut-off element 237 is provided, while the expansion element 122 intended for the expansion of the subcooling mass flow UM also serves as an expansion element for the operating adaptation unit 230 "" and therefore determines the bypass line mass flow ULM, which is bypassed by the expander 86 to the expansion pressure outlet connection 36, especially if through the Shut-off element 236 the expansion compression unit is deactivated.
  • the operating adaptation controller 238 is provided, which controls the shut-off elements 236 and 237 when the sensor 242 detects an undesired increase in the high pressure PH2.
  • the operating adaptation unit 230 "" is also formed by the bypass line 234. with the shut-off element 237, while the shut-off element 236 is arranged immediately following the expander outlet 94, so that the bypass line 234th of the
  • Lead 126 is led to the expansion pressure outlet connection 36 and opens into a line 233 between the shut-off element 236 and the expansion pressure outlet connection 36.
  • the pulsation transmission line 272 also leads into this line 233, which is led to a pulsation damper 260, which is designed in the same manner as described in connection with the first embodiment, in which case the heat transport circuit 276 is also part of the expansion system 30 and extracts heat from a bypass line between the compressor outlet 98 and the high pressure outlet connection 38 and supplies it to the heater 274.
  • the expansion system 30 ′′ is provided with the operating adaptation unit 230 ′ according to the sixth embodiment, so that in this regard reference is made to the comments on the sixth
  • Embodiment can be referred to in full.
  • a pulsation damper unit 280 is provided between the high-pressure inlet connection 34 and the high-pressure outlet connection 38, which has a damper housing 282, in which a piston 284 is arranged, which is arranged in the damper housing 282 separates the first chamber 286 from a second chamber 288, for example the first chamber 282 being connected to the high-pressure input connection 34 via a first pulsation transmission line 292 and the second chamber 288 being connected to the high-pressure output connection 38 via a second pulsation transmission line 294.
  • the pulsation damper unit 280 is thus able to dampen pulsations propagating to the high-pressure inlet connection 34 or to the high-pressure outlet connection 38 in that the piston transmits pulsation, the piston 284 preferably being mounted between two spring-elastic damping elements 296 and 298 is that in the
  • Chambers 286 and 288 are arranged.
  • a seventh embodiment of an operation adaptation unit 230, shown in FIGS. 11 and 12, is based in principle on the fourth
  • Embodiment of the operation adaptation unit 230 in which case the operation adaptation unit 230. a bypass line 234.
  • the 3/2-way valve 235 likewise being controlled by the operating adaptation controller 238, which detects, for example, the high pressure of the expansion mass flow EM before it enters the expander.
  • the expansion element 122 which is actually intended for the expansion of the supercooling mass flow UM, serves as an expansion element for this operation adaptation unit 230 in the case of the activated operating adaptation unit 230 "" emergency operation.
  • the expansion unit 32 ′′ is modified in such a way that the branch 116 ′′ between the high-pressure input connection 34 and the
  • Input 104 of the supercooling unit 102 is arranged and thus the The subcooling mass flow UM is branched off from the total mass flow G before flowing through the subcooling unit 102, the shut-off element 124 and the expansion element 122 being provided in the same way as in the preceding exemplary embodiments, which between the branch 116 ′ and the inlet 112 for the counterflow flowing through the subcooling unit 102 are arranged.
  • Controller 132 is controlled in the same manner as in the first embodiment.
  • This third exemplary embodiment of the expansion unit can also be used with various operating adaptation units, for example with one
  • Operation adjustment unit 230 ' according to the second embodiment, and the expansion element 232 provided.
  • the expansion unit 32 can also be used with operational adaptation units
  • Expander unit 32 "provided the mass flow return 240, which has already been described in connection with the first embodiment.
  • Compressor bypass 240 'realized which has already been explained in connection with the third embodiment of the operating adaptation unit 230 "in connection with FIG. 6.
  • the expansion unit 32 with an operating adaptation unit 230 'which is arranged directly on the expansion system 30" and whose bypass line 234' is between it the high pressure inlet port 34 and the expansion pressure outlet port 36.
  • shut-off valve 23 which can be activated to deactivate the expansion compression unit 84, is still integrated into the expansion system 30 ′′.
  • the expansion element 232 is controlled by means of the controller 132 in the first embodiment of the operating adaptation unit 230 described in connection with FIGS. 1 and 2.
  • the third exemplary embodiment is provided with the first embodiment of the operating adaptation unit 230, with respect to which reference is made to the above explanations for this first embodiment.
  • Embodiments of the operational adaptation unit can be used.
  • the third leads In contrast to the first embodiment, the third leads
  • the expansion line 42 does not go directly to the cooling stage 62, but to an intermediate pressure collector 44, in which a bath 46 of liquid refrigerant is formed at expansion pressure PE, from which liquid refrigerant via a liquid line 48 of the cooling stage 62 "is supplied, which in this case includes not only the heat-absorbing heat exchanger 64, but also a shutdown element 68 and an expansion element 66.
  • a gas volume 52 of refrigerant is formed in the intermediate pressure collector 44 above the bath 46, from which an additional mass flow Z is fed to the suction line 74 via an expansion element 54.
  • Expansion device 54 is adjustable.
  • a high-pressure discharge line 28 is also assigned a pulsation damper 260 which corresponds to the pulsation damper 260 shown in the first exemplary embodiment of the refrigerant circuit 10 according to FIG. 1 and assigned to the expansion line 42, so that its function is full -
  • pulsation damper 260 corresponds to the pulsation damper 260 shown in the first exemplary embodiment of the refrigerant circuit 10 according to FIG. 1 and assigned to the expansion line 42, so that its function is full -
  • the pulsation damper 260 can also be in the area of the
  • Expansion unit 32 arranged or even integrated into the expansion system 30.
  • a fourth exemplary embodiment of a refrigerant circuit 10 ′′ according to the invention shown in FIG. 17, the elements which are identical to those of the first and third exemplary embodiments of the refrigerant circuit are provided with the same reference symbols, so that with regard to the
  • the fourth embodiment of the refrigerant circuit 10 ′′ is also provided with the first embodiment of the operating adaptation unit 230, although all further embodiments could also be used.
  • the fourth embodiment is one instead of the pulsation damper 260
  • Pulsation damper unit 280 is provided, which in this embodiment is connected in parallel with the heat exchanger 22 and thus dampens pulsations between the high pressure line 18 and the high pressure line 28.
  • the pulsation damper unit 280 is of identical design to that integrated into the third exemplary embodiment of the expansion unit 32 ′′
  • Pulsation damper unit 280 (FIG. 10), so that full reference can be made to the above statements in this regard.
  • a throttle 302 is also provided between the second pulsation transmission line 294 and the high-pressure line 18 in order to obtain an improved damping effect.
  • the additional mass flow Z from the gas volume 52 is not fed directly to the suction pressure line 74 via the expansion element 54, but is again passed through a subcooler 58 provided in the liquid line 48, which cooler in the liquid line 48 flowing main mass flow H again supercooled.
  • cooling stage 62 ′′ is designed, for example, as a normal cooling stage and, in addition, a deep-freezing stage 212 is also provided, which has a heat-absorbing heat exchanger 214 and a shutdown element 218 and an expansion element 216.
  • the refrigerant expanded in the freezer stage 212 is fed via a suction pressure line 224 to a freezer compressor unit 222, which compresses the refrigerant again to such an extent that it can be fed to the suction pressure line 74 for the refrigerant compressor unit 12 for compression to high pressure.
  • a subcooler 226 is preferably also provided in the suction pressure line 224 of the freezer compressor unit 222, which subcooles the refrigerant supplied via the liquid line 48 to the freezer stage 212 again before it enters the freezer stage 212, specifically by means of the outlet and exit from the freezer stage 212 Expanded refrigerants carried in the suction pressure line 224.
  • the intermediate pressure controller 55 To control the temperature of the refrigerant in the high-pressure line 28 and, for example, the respective outside temperature, and to use the intermediate pressure controller 55 to merely define a constant intermediate pressure PM in the intermediate pressure collector 44.
  • the increase in efficiency of the refrigerant circuit can be achieved by the above-mentioned detection of the inlet pressure EP of the compressor stage 88 by means of the controls 132, 138.
  • the refrigerant circuit 10 according to the invention can also be operated with regard to the achievable COP, that is to say the ratio of cooling power to the mechanical power used, in particular in summer, and with regard to the expansion of the functional operation of the
  • the expansion compression unit Optimize the expansion compression unit, particularly in winter operation, so that an additional operating condition-related regulation of the intermediate pressure PM takes place, which affects the inlet pressure EP of the compressor stage 88 on the basis of the volume ratios of the expansion compression unit 84.
  • the intermediate pressure PM is regulated, for example, by means of the intermediate pressure controller 55 and the expansion element 54 to a pressure value which, on the one hand, results from a basic value, which is generally defined once, and supplementary values for this basic value which vary depending on the operating state.
  • the basic value for CO2 as a refrigerant is in the range of 30 bar to 45 bar, so that a value from this range, for example 35 bar, is specified as the basic value, and the additional values for CO2 as refrigerant are in the range of 0 , 5 bar to 7 bar.
  • the surcharge values could in principle be fixed values from the range of the surcharge values provided for this, but it is particularly favorable if the surcharge values vary within this intended range due to the operating condition.
  • the additional values having positive values in summer operation and negative values in winter operation, so that the values for CO2 as refrigerant in summer operation are in the range from 0.5 bar to 7 bar and at Winter operation is in the range of -0.5 bar to -7 bar.
  • the size of the additional values are dependent on the values lying in the control range of the high pressure PH2 and therefore vary depending on the values of the high pressure PH2.
  • the additional values are higher for high values of the high pressure than for low values of the high pressure.
  • there are additional values in the range from +0.5 bar to +3 bar provided the high pressure PH2 has values in the range from 75 bar to 80 bar, and additional values in the range from +3 bar to +7 bar, provided the high pressure PH2 has values in the range greater than 80 bar, preferably values greater than 80 bar to 120 bar.
  • an additional value in the range of 3 bar is used for a high pressure PH2 in the range of 80 bar, while an additional value in the range of 5 bar is used for high pressure PH2 in the range of 90 bar.
  • the additional values for winter operation are, for example, in the range from -0.5 bar to -3 bar, provided the high pressure PH2 is in the range from 55 bar to 65 bar and the additional values are in the range from -3 bar to -5 bar, provided the high pressure PH2 is below 50 bar to 40 bar.
  • an additional value in the range of -3 bar is used for a high pressure PH2 in the range of 60 bar and an additional value in the range of -5 bar is used for high pressure in the range of 50 bar.
  • the basic value is preferably always the same.
  • the inlet pressure EP changes at the compressor stage 88 and thus a subcooler output of the subcooling unit 102. If the intermediate pressure PM is increased, the inlet pressure EP at the compressor stage 88 increases and thus the subcooling mass flow UM and thus the subcooling power of the subcooling unit 102 are increased, so that the COP also increases.
  • the inlet pressure EP at the compressor stage 88 also drops.
  • the pressure difference at the expander stage 86 is increased and thus the functional range of the expansion compression unit 84 is also increased.
  • Intermediate pressure control 55 detects the variables, in particular the temperature and / or the pressure of the total mass flow G in the high pressure discharge line 28 and the variable of the inlet pressure EP of the compressor stage 88, and controls the intermediate pressure PM as a function thereof in order to adjust to a predefined and suitable one for the detected variables, for example in the
  • Intermediate pressure controller 55 to regulate stored value of the input pressure EP.
  • All compressor units can be any compressor or combination of compressors (parallel, in series, multi-stage).
  • one or more of the compressors can be provided with a power control, which is carried out by switching off compressors, by mechanical power control (for example switching off, in particular cyclical
  • Switching off parts (cylinder banks) of a compressor) or speed control of the compressor can take place.
  • the operational adaptation unit 230 and the expansion unit 32 comprising the expansion compression unit 84 are activated or deactivated were not discussed in detail.
  • the operating adaptation unit 230 is assigned a controllable or regulatable expansion element 232 or 122, so that the mass flow flowing through the bypass line 234 can be controlled or regulated.
  • Corresponding temperature Tamb detects and checks whether this is higher or lower than a temperature threshold TS above which the expansion unit 32 having the expansion compression unit 84 can be operated stably and below which instabilities during operation of the Expansion unit 32 having expansion compression unit 84 occur.
  • the expansion compression unit 84 is switched off and the refrigerant circuit 10 works with the operating adaptation unit 230, which variably sets the mass flow ULM through the respective bypass line 234.
  • the temperature threshold TS is preferably in the range from 15 ° C. to 20 ° C. with CO2 as the refrigerant.
  • controller 132, 138 checks according to the flow chart in FIG. 19 whether the total mass flow G, which is present at high pressure, is greater than the sum of the supercooling mass flow UM and the
  • the expansion compression unit 84 is no longer able to prevent the pressure of the high pressure PH2 from increasing.
  • the operating adaptation unit 230 is likewise activated in such a way that it adjusts the mass flow ULM flowing through the bypass line 234 in such a way that the high pressure PH2 can be kept at a constant level.
  • the expansion unit 32 comprising the expansion compression unit 84 is operated exclusively with the operating adjustment unit 230 deactivated.
  • FIGS. 21 to 23 show the refrigerant circuits 10 and expansion units 32 corresponding to FIGS. 16 to 18, which are identical in terms of their overall structure, the embodiment according to FIG. 21 being that of FIG. 16, the embodiment according to FIG 22 corresponds to that of FIG. 17 and the embodiment according to FIG. 23 corresponds to that of FIG.
  • the operating adaptation units 230 and 230 ' are identical to the operating adaptation units of FIGS. 16 to 18, but with the difference that in the bypass lines 234 and 234' for activating or deactivating them there are no controllable expansion elements 232 or 232 '. are provided, but only switching valves 231 and 231 ', which can either be opened or closed, the sound valves 231 and 231', in particular, being designed such that no pressure loss occurs in the opened, i.e. activated, state thereof, so that ultimately when activated Operating adaptation unit 230 or 230 'at the expansion pressure outlet connection 36 of the respective one
  • Expansion unit 32 high pressure PH2 is present.
  • Such a switching valve 231 or 231 ' is of simpler construction and is therefore more economical and also less expensive to operate than an expansion element 232, since no regulation is required, but rather only a signal for opening or closing is to be generated by the respective controller 132, 138.
  • control flowchart is designed as shown in FIG.
  • the temperatures Tam b detected in the area of the high-pressure side heat exchanger 22 are compared with the temperature threshold value TS and a further lower temperature threshold value TUS, which is lower than the temperature threshold value TS.
  • the temperature threshold TS is preferably C02 as the refrigerant in the range from 15 ° C to 20 ° C and the lower temperature threshold TUS is preferably in the range from 8 ° C to 12 ° C.
  • the operating adaptation unit 230 activates at time intervals, for example pulse-width modulated and is deactivated to keep the high pressure PH2 at an appropriate level.
  • the expansion compression unit 84 is deactivated, ie switched off, and the operating adaptation unit 230 is permanently activated, in connection with, in particular, permanent opening of the valve 231 in the corresponding bypass line 234th At temperatures Tamb that are greater than the temperature threshold TS, only the respective expansion unit 32 is operated with the expansion compression unit 84.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

L'invention concerne un circuit frigorifique, comprenant au moins un compresseur frigorifique, lequel comprime à haute pression un fluide frigorifique amené à un raccord d'aspiration, de sorte qu'un débit massique de compresseur du fluide frigorifique comprimé à haute pression sort par un raccord de pression, au moins un échangeur de chaleur côté haute pression dissipant la chaleur et pourvu d'une entrée, à laquelle le circuit frigorifique amène le débit massique de compresseur, et d'une sortie, de laquelle sort un débit massique total refroidi de fluide frigorifique, au moins une unité d'expansion, et au moins un étage de refroidissement pourvu d'au moins un échangeur de chaleur absorbant la chaleur, auquel le circuit frigorifique amène un débit massique principal compris par le débit massique de pression d'expansion mis en expansion par l'unité d'expansion, ainsi qu'une unité d'adaptation de fonctionnement associée au circuit frigorifique.
EP19746487.8A 2018-08-01 2019-08-01 Circuit frigorifique Pending EP3830500A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PCT/EP2018/070919 WO2020025135A1 (fr) 2018-08-01 2018-08-01 Circuit frigorifique
PCT/EP2019/070823 WO2020025770A2 (fr) 2018-08-01 2019-08-01 Circuit frigorifique

Publications (1)

Publication Number Publication Date
EP3830500A2 true EP3830500A2 (fr) 2021-06-09

Family

ID=63108558

Family Applications (2)

Application Number Title Priority Date Filing Date
EP18750160.6A Pending EP3830499A1 (fr) 2018-08-01 2018-08-01 Circuit frigorifique
EP19746487.8A Pending EP3830500A2 (fr) 2018-08-01 2019-08-01 Circuit frigorifique

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP18750160.6A Pending EP3830499A1 (fr) 2018-08-01 2018-08-01 Circuit frigorifique

Country Status (2)

Country Link
EP (2) EP3830499A1 (fr)
WO (2) WO2020025135A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113865133B (zh) * 2021-09-17 2022-08-23 珠海格力电器股份有限公司 一种空调系统及其控制方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8322150B2 (en) * 2006-03-27 2012-12-04 Carrier Corporation Refrigerating system with parallel staged economizer circuits discharging to interstage pressures of a main compressor
JP5064517B2 (ja) * 2008-02-20 2012-10-31 パナソニック株式会社 冷凍サイクル装置
JP5628892B2 (ja) * 2009-04-01 2014-11-19 リナム システムズ、リミテッド 廃熱空調システム
WO2010140324A1 (fr) * 2009-06-02 2010-12-09 三菱電機株式会社 Dispositif à cycle de réfrigération
US8327651B2 (en) * 2009-07-07 2012-12-11 Hamilton Sundstrand Corporation Transcritical fluid cooling for aerospace applications
CN104114959B (zh) * 2011-12-23 2021-02-05 Gea博客有限公司 压缩机
JP6276000B2 (ja) * 2013-11-11 2018-02-07 株式会社前川製作所 膨張機一体型圧縮機及び冷凍機並びに冷凍機の運転方法
DE102015214705A1 (de) * 2015-07-31 2017-02-02 Technische Universität Dresden Vorrichtung und Verfahren zum Durchführen eines Kaltdampfprozesses
US20170174049A1 (en) * 2015-12-21 2017-06-22 Ford Global Technologies, Llc Dynamically controlled vapor compression cooling system with centrifugal compressor

Also Published As

Publication number Publication date
WO2020025770A3 (fr) 2020-04-02
WO2020025770A2 (fr) 2020-02-06
WO2020025135A1 (fr) 2020-02-06
EP3830499A1 (fr) 2021-06-09

Similar Documents

Publication Publication Date Title
DE602004009355T2 (de) Kältegerät
EP1886075B1 (fr) Appareil frigorifique
DE102006050232B3 (de) Kälteanlage
DE102006062834B4 (de) Ejektorkreislaufsystem
DE60112866T2 (de) Kühlungskreislauf und Steuerungsverfahren dafür
DE112005000931B4 (de) Ejektorpumpen-Kühlkreisvorrichtung
DE60016837T2 (de) Überkritischer Dampfkompressionskreislauf
DE60314559T2 (de) Verfahren zum Erhöhen der Leistungsfähigkeit einer Dampfverdichtungsanordnung mittels Verdampferheizung
DE69722146T2 (de) Kälteanordnung mit einem Verdichter für ein- oder mehrstufigen Betrieb mit Leistungsregelung
DE60320036T2 (de) Kühlvorrichtung
DE10356447A1 (de) Kältekreislaufvorrichtung
DE102015112439A1 (de) Kälteanlage
DE10347748A1 (de) Mehrfachzonen-Temperatursteuersystem
WO2014023694A2 (fr) Procédé de réglage d'un compresseur d'une installation frigorifique et installation frigorifique
EP3099985B1 (fr) Système de réfrigération
DE3500800A1 (de) Zweistufige kaeltemittelanlage
EP3830500A2 (fr) Circuit frigorifique
EP3574269B1 (fr) Unité d'expansion a intégrer dans un circuit de réfrigération
DE102007013485B4 (de) Verfahren zur Regelung einer CO2-Kälteanlage mit zweistufiger Verdichtung
DE202007017723U1 (de) Anlage für die Kälte-, Heiz- oder Klimatechnik, insbesondere Kälteanlage
DE202006014246U1 (de) Kaltdampf-Kältemaschine
DE10338388B3 (de) Verfahren zur Regelung einer Klimaanlage
WO2015110632A1 (fr) Système de réfrigération
EP4160109A1 (fr) Système de refroidissement et appareil de laboratoire doté d'un système de refroidissement
EP3071903B1 (fr) Tête froide pour refroidisseur cryogénique

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210128

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20221122

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230517

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20240305