Installation for storing and supplying liquid carbon dioxide as refrigerant, particularly for filling air conditioning systems

Abstract

A system for storing and supplying liquid carbon dioxide as a refrigerant comprises a carbon dioxide tank system with at least one storage tank in which liquid carbon dioxide can be stored at a temperature in a first temperature range and at a pressure in a first pressure range, and which has at least one inlet connection for supplying liquid carbon dioxide, e.g., from a tank truck, and at least one outlet connection; at least one pressure boosting station, which is connected at at least one inlet connection via a pipeline to the outlet connection of the storage tank and is designed to provide liquid carbon dioxide at an outlet connection of the pressure boosting station at a pressure increased compared to the first pressure range in a second pressure range;A temperature control arrangement comprising at least one carbon dioxide buffer storage tank connected directly or indirectly via at least one pipeline to the outlet port of the pressure boosting station, designed to hold liquid carbon dioxide in the carbon dioxide buffer storage tank at a temperature higher than the first temperature range in a second temperature range and at a pressure in a third pressure range; and at least one carbon dioxide recooler connected via at least one pipeline to an outlet port of the carbon dioxide buffer storage tank, designed to supply liquid carbon dioxide to at least one consumer via an outlet port at a temperature in a setpoint temperature range and at a pressure in a setpoint temperature range.

Description

[0001] The present invention relates to a system for storing and supplying liquid carbon dioxide (CO₂; hereinafter generally referred to as CO₂) as a refrigerant, in particular for filling air conditioning systems. This primarily concerns air conditioning systems in the automotive sector. The present invention therefore also relates to an R744 supply concept for filling air conditioning systems in the automotive sector and a system designed for this purpose for storing and supplying the refrigerant R744.

[0002] Carbon dioxide, a natural refrigerant, has a long tradition in refrigeration technology, dating back to the 19th century. More recently, it has experienced a renaissance as an alternative refrigerant, designated R744. Carbon dioxide as a refrigerant is environmentally friendly because it has a very low global warming potential (GWP) of one and an ozone depletion potential (ODB) of zero. Furthermore, carbon dioxide is readily available from natural sources and thanks to technological advancements in its recovery from process gas. Compared to conventional fluorinated refrigerants, carbon dioxide is environmentally friendly and cost-effective. It is non-flammable, non-toxic, and colorless.

[0003] The high operating pressure of this refrigerant, its low critical point, the possibility of dry ice formation when the triple point is undershot, and its comparatively high stagnation pressure present significant challenges. This results in correspondingly demanding requirements for the system used to store and supply the refrigerant, and of course also for the devices and systems that use this refrigerant, such as a vehicle air conditioning system.

[0004] According to the invention, the use of special supply technology for liquid carbon dioxide R744 (CO2) is proposed, which advantageously meets these requirements.

[0005] The invention specifically provides a system for storing and supplying liquid carbon dioxide as a refrigerant, characterized by the features of claim 1 of the appended set of claims. Advantageous embodiments of the system are defined in the dependent claims of the set of claims.

[0006] Preferably, the first temperature range is the range from minus 25 °C to minus 20 °C.

[0007] Preferably the first pressure range is the range from 16 bar to 20 bar.

[0008] The third print area can essentially correspond to the second print area. The target print area can essentially correspond to the third print area.

[0009] Preferably, the second pressure range and / or the third pressure range and / or the target pressure range is the range from 60 bar to 70 bar.

[0010] The third temperature range can essentially correspond to the second temperature range. The target temperature range can essentially correspond to the third temperature range.

[0011] Preferably, the second temperature range and / or the third temperature range and / or the target temperature range is the range from 15 °C to 20 °C.

[0012] The invention will be explained in more detail below with reference to an exemplary embodiment, to which reference is made to the accompanying drawing, the figures of which show the following: Fig. 1 shows an overview of a flowchart of an example of a system according to the invention. Fig. 2 shows in the partial figures Fig. 2a to Fig. 2g enlarged sections of the flowchart of the Fig. 1 .

[0013] An advantageous system for storing and distributing the refrigerant R744 (CO2 / liquid carbon dioxide) of an exemplary embodiment, for example, according to or based on the Figure 1 and 2 In accordance with the present invention, the following main components may be included, for example: CO2 tank system (1) CO2 pressure boosting station (2), preferably with a redundant compressor CO2 air heater (3) CO2 buffer tank (4) with heating and cooling for conditioning the CO2 CO2 recooler (5), i.e., a so-called chiller, preferably redundant, particularly advantageous upstream of any R744 filling technology on an assembly line Supply pipelines (6) between storage tank → pressure boosting station → air heater → buffer tank → recooling upstream of the filling technology → filling technology

[0014] Liquid carbon dioxide is stored in the pressurized carbon dioxide tank system (1). Temperature and pressure typically range between -25 and -20 °C and 16 and 20 bar. The tank system can be double-walled with an inner stainless steel tank. The space between the walls can be filled with a highly insulating material and additionally maintained under high vacuum. The fill level can be transmitted to a supplier via remote data transmission. Refilling of the tank system can then be carried out automatically by a contracted liquid CO2 distribution service, depending on the tank level and consumption profile.

[0015] Carbon dioxide is supplied via an insulated pipeline (6) to a pressure boosting station (2) or to one of several pressure boosting stations (2). This station pumps the CO2 into the downstream pipeline (6) and increases the pressure to the process-related required value, typically around 70 bar. The pressure boosting station(s) is / are redundantly designed for maximum availability. If one compressor fails, the plant control system automatically switches to the redundant compressor within the pressure boosting station.

[0016] After pressure increase, the CO2 is warmed to approximately ambient temperature using an air-heated heater (3) and then pumped into the downstream buffer tank (4). This reduces the electrical energy required and lowers the CO2 footprint for bringing the R744 to the process-related temperature.

[0017] In the downstream, insulated buffer tank (4), R744 is stored under the process-related parameters required and kept ready for transfer to the filling systems. An integrated, redundant heating system and a chiller ensure compliance with the process parameters even under varying ambient temperatures. The buffer tank is filled by weight using weighing technology.

[0018] After transport through the pressure line (6) to the production hall and the consumers, the liquid carbon dioxide is cooled to the desired temperature level directly before the filling system on the line via at least one recooling unit and at least one heat exchanger of the CO2 recooler or chiller (5) (or one of several CO2 recoolers or chillers (5)) and then transferred to the filling system. The pressure and temperature of the carbon dioxide are measured and recorded before the main unit.

[0019] Advantageously, the system for storing and distributing the refrigerant R744 (CO2 / liquid carbon dioxide) can meet a suitable safety concept.

[0020] Due to its design and the materials used, the carbon dioxide tank system can advantageously be considered type-tested. The pressure in the tank system can be kept constant by a pressure regulator. However, the pressure in the tank system could rise due to the influx of ambient heat if no CO2 is drawn for an extended period.

[0021] To reliably prevent the maximum permissible pressure of the tank system from being exceeded during heating, the system can be equipped with redundant mechanical safety valves. To prevent overfilling by a CO2 tanker truck, the tank system can be fitted with a safety shut-off valve.

[0022] Liquefied carbon dioxide under pressure heats up in the pipelines and system components when there is no or minimal withdrawal, or during prolonged periods of inactivity. This leads to a pressure increase. To prevent the pressure from exceeding the permissible pressure of the components, all system sections where carbon dioxide is or could be trapped during normal operation can be equipped with component-tested safety valves.

[0023] It is advantageous to adjust the discharge pressure of the safety valves under the expert supervision of an employee of a certification or monitoring organization (such as TÜV).

[0024] Safety valves strategically placed within the building serve to release the pressure increase caused by thermal expansion in the event of incorrect operation of shut-off valves. The discharge lines can advantageously be routed, for example, above the roof.

[0025] The pipelines used are preferably made of stainless steel. The individual pipe segments can be welded together for convenience. The pipeline should be tested for strength and leak tightness after completion and before commissioning. Due to the welded joints, the pipeline is considered permanently leak-tight.

[0026] The following are examples of possible specific configurations of the aforementioned components of the plant, without limiting generality: CO2 refueling station (1)

[0027] Tank system: Horizontal or vertical vacuum-insulated tank. Geometric volume: as required, for example, between 6,400 and 30,000 liters (L) (larger volumes, such as 100,000 liters, are not excluded). Tank height: for example, 8,150 mm. Tank diameter: for example, between 1,600 mm and 3,600 mm. Max. operating pressure: 22 bar. Self-evaporation: 0.35% CO2 / day (without recooling, depending on tank size). Outer tank material: structural steel, S235 JRG 2 / 1.0038. Inner tank material: stainless steel, X5CrNi1810 / 1.4301.

[0028] The tank system preferably consists of a double-walled, vacuum-insulated pressure tank equipped with all fittings and control devices required for automatic operation. The inner tank is preferably made of stainless steel, the outer tank preferably of structural steel.

[0029] The system can be designed for outdoor installation and placed on a concrete foundation. CO2 pressure boosting station (2)

[0030] CO2 pressure boosting station with pneumatic drive for outdoor installation in a heated control cabinet. The system can be advantageously equipped with two redundant compressors.

[0031] Example technical data: Standard delivery rate (continuous operation): max. 80 kg CO2 / h (at max. 70 bar) Compressed air consumption: approx. 0.4 Nm3 / kg CO2 Compressed air network pressure: 6 bar Number of compressors: 2

[0032] Dimensions of compressor station (approximate, for example): Depth: 500 mm Width: 1,200 mm Height: 1,900 mm CO2 air heater (3) Gas heater for carbon dioxide, e.g. type L400-8F3-HD

[0033] Air-heated high-pressure finned tube heater with medium-carrying stainless steel piping, preferably designed for outdoor installation.

[0034] Example performance data: Pressure rating: PS 400 bar Electrical power consumption: none Connection voltage: none Dimensions (L x W x H): e.g. approx. 1,120 x 720 x 4,000 mm CO2 buffer tank (4)

[0035] Insulated buffer tank, preferably in a horizontal design. The tank can advantageously be mounted on an electronic load cell, which may be installed in a (possibly galvanized) steel frame. The tank pressure can be maintained within the process-related required range by a built-in, redundant heating system and a chiller.

[0036] Example performance data: Pressure rating: PS 80 bar Insulation: 100 mm with sheet metal casing, 1 mm Tank material: P355NL or similar Heating: e.g., two heating coils with approx. 5.0 kW heating output each Refrigeration unit: approx. 2.0 kW Supply voltage: 400 V / 50 Hz Dimensions (L x W x H): approx. 2,400 x 2,500 x 2,000 mm Operating weight: approx. 4,000 kg

[0037] These are examples for illustrative purposes only. The design of the buffer tank (size, volume, dimensions) must be selected based on consumption and the specifications of the filling system. CO2 recooler in front of the filling system / Chiller (5)

[0038] Recooler for liquid carbon dioxide to ensure the transfer specification at the transfer point to the consumers, especially the vehicle filling systems.

[0039] The number of recoolers included in the system depends on the number of consumers or filling stations. Recooling is achieved using water or an ethylene glycol / water mixture as the heat transfer medium. In conjunction with the integrated buffer tank, compliance with the R744 transfer specification is ensured even with highly fluctuating demand profiles. The heat transfer medium tank is unpressurized.

[0040] The cooling unit can advantageously consist essentially of: Buffer tank, frequency-controlled chiller, redundant circulation pump, water / CO2 heat exchanger, electrical control, shut-off and safety valves

[0041] Regarding the recooler, the following performance data is considered, for example: Pressure rating: PS 10 / 100 bar Total electrical power consumption: 5.0 kW Supply voltage: 400 V / 50 Hz Maximum operating current: 16 A Refrigerant: R513A Refrigerant quantity: 3.0 kg Dimensions (L x W x H): 1000 x 1500 x 2000 mm each Weight: approx. 500 kg each

[0042] Regarding the heat exchanger, the following performance data is considered, for example: Media: CO2 / Water-ethylene glycol mixture or pure water Number of plates: 40 Volume: 2 x 2 liters Weight: 28 kg Dimensions (L x W x H): 98 x 425 x 203 mm Insulation: Armaflex (if applicable) CO2 pipeline construction (6)

[0043] A) Tank system -> Pressure boosting station: Stainless steel piping, welded. B) Pressure boosting station -> Heating -> Buffer tank -> CO2 filling system including recooler and heat exchanger at the inlets of the R744 filling systems on the filling platform above the assembly line: Stainless steel piping, welded.

[0044] Relevant key data: Pressure rating: ND: PS 40 / HD: PS 100 Nominal diameter: DN 15 / 25 (18x1.5; 28x1.5 mm) Material: 1.4571 Insulation: not mandatory

[0045] The pipelines include the necessary fittings and safety valves for safe plant operation as well as for maintenance and repair purposes. Electrical Engineering / Automation (7)

[0046] For controlling the supply system, a control system can be used that can advantageously provide, for example, the following functions: 1 General Functions 1.1 Messages

[0047] All hazard, fault, warning, and maintenance messages are combined into a collective fault message, causing an indicator light on the control cabinet to flash. The messages are displayed individually on the operator panel. Messages can be distinguished, for example, as follows: 1.1.1 Operational notifications

[0048] Operational messages are information about the system status without any further action regarding the system and are only displayed.

[0049] An operational message has no effect on the collective fault lamp. 1.1.2 Maintenance messages

[0050] Maintenance messages are displayed on the control unit. No switching operations are performed.

[0051] The collective fault indicator light is flashing. This state will remain until the fault is rectified and acknowledged. 1.1.3 Warning messages

[0052] Warning messages are displayed on the control unit and can shut down the affected system. The collective fault indicator flashes. This state remains until the fault is rectified and acknowledged. 1.1.4 Fault messages without system shutdown

[0053] Fault messages without system shutdown are signaled on the control unit and only shut down the faulty unit.

[0054] The collective fault indicator light is flashing. This state will remain until the fault is rectified and acknowledged. 1.1.5 Fault messages with system shutdown

[0055] Fault messages requiring system shutdown are signaled on the control unit and lead to the immediate shutdown of the system.

[0056] The collective fault indicator light is flashing. This state will remain until the fault is rectified and acknowledged. 1.1.6 Danger messages with system shutdown

[0057] Danger messages are signaled on the control unit and lead to the immediate shutdown of the system or to reaching a safe state (e.g. frost protection circuit).

[0058] The collective fault indicator light is flashing. This state will remain until the fault is rectified and acknowledged. 1.2 Switching commands

[0059] All switching commands are monitored by feedback with a runtime check. If no feedback is received after the runtime has elapsed, the switching command is reported as faulty. This faulty switching command can lead to the shutdown of systems or system components. 2.1 Automation system (DDC)

[0060] A DDC system can be advantageously used, allowing DDC programs to be edited, downloaded, and uploaded from the control room via the system bus (Ethernet). The automation stations, preferably using standardized and tested function blocks for building services engineering and other building technology systems, autonomously and reliably fulfill all automation and optimization tasks. The modular software components from a standardized library can be freely combined and configured with the necessary operating parameters for each individual system, depending on the requirements.

[0061] A Siemens 1515F-2PN / DP digital control controller (DDC) with IM155-6PN ST expansion modules can be conveniently installed in the control cabinet. The system can be operated and monitored locally via a touch panel, such as the 1200 Comfort model. The DDC can be programmed in the TIA Portal V16 and connected to the building management system (BMS) via an Ethernet interface.

[0062] Alternatively, other controllers (e.g. Rockwell, B&R, Bosch, etc.) can also be used.

[0063] The system can be advantageously connected to a higher-level control system. This control system can then take over higher-level functions for optimal operational management and can serve for the central operation and monitoring of all building services systems. The control system could provide access to all connected systems and handle optimization, management, and statistical functions. 2.2 Level monitoring of the supply tank

[0064] The storage tank (1) preferably operates autonomously. The fill level and pressure of the supply tank could, by default, only be displayed on-site. However, a display in the main cabinet is also possible and practical. It may be advantageous to communicate the tank fill level directly to the CO2 supplier via remote data transmission. 2.3 Pressure increase (2)

[0065] The compressors used are, in principle, suitable for a wide variety of applications. They serve to convey liquefied gases under pressure and compress them to high pressures. The compressors can advantageously be driven by compressed air in the range of 1 to 10 bar and are released depending on the mass in the buffer tank.

[0066] For example, settings: Mass < 400 kg START compressors Mass > 800 kg STOP compressors 2.4 Buffer tank (4)

[0067] The buffer storage tank keeps the refrigerant CO2 available for consumers or production.

[0068] A shut-off ball valve can be provided in front of the buffer tank, which closes in case of emergency stop, gas warning and when the buffer tank fill level reaches maximum.

[0069] A further shut-off ball valve can be provided downstream of the buffer tank, which closes in the event of an emergency stop and gas warning.

[0070] The buffer tank's fill level can be conveniently measured in kg and displayed in the main cabinet. The buffer tank's pressure can be measured in bar and displayed in the main cabinet. 2.5 Gas warning system in use

[0071] For gas monitoring, a gas warning system can be advantageously used, which includes, for example, an evaluation unit of type Regard 2410 and sensors of type PIR 7000. 2.6 Chiller / CO2 Recooler (5)

[0072] Water-cooled, compact chillers, readily available with pre-piped and pre-wired units, are suitable for this application. Common designs and sizes can be used, for example, with a scroll compressor, separate condenser and fan, and robust coaxial evaporator. It is recommended to provide these chillers with relatively large tank volumes compared to their comparatively low capacity, making them suitable for a wide range of applications. The chillers can be equipped with proven compact controllers.

[0073] The proposed overall concept and appropriately designed, precise measurement and control technology with application-specific microprocessor control enable precise temperature control. Upon request, the chillers are activated, and faults are displayed on the main cabinet, operator panel, and control system. 2.7 BMZ report

[0074] A fire alarm control panel, which can be used to advantage, can signal the requirements for hazard shutdown via an open contact.

[0075] The switchgear of the CO2 supply system can signal, with a closed potential-free contact, that there is no main alarm from the gas warning system. 2.8 Emergency Stop Button

[0076] An emergency stop button can be installed externally in the tank area and another on the control cabinet, both operating within a single safety circuit and shutting down all components. The emergency stop can be resettable at the control cabinet in the technical control room. Example parts / component list

[0077] In addition to the Figure 1 and 2 This document provides a list of parts and components suitable for the implementation of such a system, the designations of which refer to those described in the... Figure 1 and 2 included designations refer to: CO2 tank system (1) Vacuum insulated storage container Depending on demand Booster station (2) redundant pump station for pressure boosting to 70 bar Size depends on requirements Air heater (3) Atmospheric evaporator Size depends on requirements Control cabinet (7) Control cabinet for controlling the system according to customer specifications CO2 buffer tank (4) Insulated pressure vessel with integrated temperature control (heating and cooling) 1.450ltr CO2 recooler (5) Heat exchanger unit with connected chiller Size depends on requirements CO2 pipeline Stainless steel pipe, partially insulated, connecting the buffer tank (4) and the recooler (5). Dn 25 H01 Shut-off valve, manually operated DN 25 H02 Drain ball valve - welded DN 15 H03 Drain ball valve - welded DN 15 H04 Shut-off valve, manually operated DN 25 H05 Drain ball valve - welded DN 15 H06 Shut-off valve, manually operated DN 40 H07 Shut-off valve, manually operated DN 20 H08 Shut-off valve, manually operated DN 40 H09 Shut-off valve, manually operated DN 40 H10 Shut-off valve, manually operated DN 40 H11 Shut-off valve, manually operated DN 15 H12 Drain ball valve - welded DN 15 H16 Shut-off valve, manually operated DN 15 H17 Shut-off valve, manually operated DN 15 H18 Drain ball valve - welded DN 15 H25 Shut-off valve, manually operated DN 15 H26 Drain ball valve - welded DN 15 H27 Shut-off valve, manually operated DN 15 H31 Shut-off valve, manually operated DN 20 H32 Shut-off valve, manually operated DN 20 H33 Shut-off valve, manually operated DN 20 H38 Shut-off valve, manually operated DN 20 H39 ball valve, general DN20 H12 Shut-off valve, manually operated DN 15 SV01 20 bar Corner-type safety valve DN 25 SV02 20 bar Corner-type safety valve DN 25 SV03 80 bar Corner-type safety valve DN 25 SV06 80 bar Corner-type safety valve DN 25 SV07 80 bar Corner-type safety valve DN 25 SV09 80 bar Corner-type safety valve DN 25 PVO2 with GOS ± Ball valve with pneumatic actuator, spring-closing, including position indicator DN 25 D02 Pressure reducing valve in general DN 20 PI 01 Manometer unit 0-100 bar PI 03 Manometer unit 0-10 bar PISA 03 Electronic pressure measuring device with display 0-100 bar PISA 05 Electronic pressure measuring device with display 0-100 bar R01 non-return valve DN 25 TISA01 Electronic temperature measurement with display WICR01 Weighing technology as level measurement of the buffer tank (4)

[0078] Of course, other parts or components can be used in the actual implementation of a system according to the invention, and parts or components can also be omitted or / and added.

Claims

1. A system for storing and supplying liquid carbon dioxide as a refrigerant, comprising: - a carbon dioxide tank system (1) with at least one storage tank in which liquid carbon dioxide can be stored at a temperature in a first temperature range and at a pressure in a first pressure range, and which has at least one inlet connection for supplying liquid carbon dioxide from a tank truck and at least one outlet connection; - at least one pressure boosting station (2) which is connected to the outlet connection of the storage tank at at least one inlet connection via a pipeline (6) and is designed to provide liquid carbon dioxide at an outlet connection of the pressure boosting station (2) at a pressure in a second pressure range which is higher than the first pressure range;- a temperature control arrangement with at least one carbon dioxide buffer storage (4) connected directly or indirectly via at least one pipe (6) to the outlet connection of the pressure boosting station (2), which is designed to store liquid carbon dioxide in the carbon dioxide buffer storage (4) at a temperature higher than the first temperature range in a second temperature range and at a pressure in a third pressure range; - at least one carbon dioxide recooler (5) connected to an inlet connection via at least one pipe (6) to an outlet connection of the carbon dioxide buffer storage (4), which is designed to provide liquid carbon dioxide to at least one consumer at a temperature in a target temperature range and at a pressure in a target temperature range via an outlet connection of the carbon dioxide recooler (5); 2. Plant according to claim 1, characterized in thatthe first temperature range is or includes the range from minus 25 °C to minus 20 °C and / or that the first pressure range is or includes the range from 16 bar to 20 bar.

3. Plant according to one of claims 1 or 2, characterized in that the third pressure range essentially corresponds to the second pressure range and / or that the target pressure range essentially corresponds to the third pressure range.

4. Plant according to one of claims 1 to 3, characterized in that the second pressure range and / or the third pressure range and / or the target pressure range is or includes the range 60 bar to 70 bar.

5. Plant according to one of claims 1 to 4, characterized in that the third temperature range essentially corresponds to the second temperature range and / or that the target temperature range essentially corresponds to the third temperature range.

6. Plant according to one of claims 1 to 5, characterized in thatthe second temperature range and / or the third temperature range and / or the target temperature range is or includes the range 15 °C to 20 °C.

7. Plant according to one of claims 1 to 6, characterized in that the temperature control arrangement comprises at least one air-heated heater (3) connected upstream of the carbon dioxide buffer storage (4).

8. Plant according to one of claims 1 to 7, characterized in that the carbon dioxide buffer storage (4) has at least one heating unit integrated therein, for example comprising an electrical resistance heater, and / or that the carbon dioxide buffer storage (4) has at least one cooling unit, for example comprising a refrigeration machine.

9. Plant according to one of claims 1 to 8, characterized in that the carbon dioxide buffer storage (4) is designed with at least one weighing device, on the basis of which the carbon dioxide buffer storage (4) can be filled with liquid carbon dioxide in a weight-controlled manner.

10. Plant according to one of claims 1 to 9, characterized in that the carbon dioxide recooler (5) has at least one cooling unit which serves to cool a liquid heat transfer medium which is in heat exchange connection with the liquid carbon dioxide flowing through at least one heat exchanger in order to provide the liquid carbon dioxide to the at least one consumer at a temperature in the target temperature range.

11. Plant according to one of claims 1 to 10, characterized in that the at least one consumer is a filling station belonging to the system for filling an air conditioning system, in particular a vehicle air conditioning system in a motor vehicle, with liquid carbon dioxide as a refrigerant.

12. Plant according to one of claims 1 to 11, characterized bya system control system designed or programmed to control components of the system such that the liquid carbon dioxide at reference locations in the system corresponds to temperature and pressure parameters provided; wherein the system control system is preferably designed or programmed to bring the pressure of the liquid carbon dioxide to the pressure in the second pressure range by appropriately controlling at least one compressor of the pressure boosting station (2) and / or to bring the temperature of the liquid carbon dioxide in the carbon dioxide buffer storage (4) to the temperature in the second temperature range and to maintain it in the second temperature range by appropriately controlling at least one component of the temperature control system, in particular its heating unit and / or its cooling unit.

13. Plant according to claim 12, characterized in thatThe system control is designed or programmed to cool the liquid carbon dioxide as required by appropriately controlling at least one component of the carbon dioxide recooler (5), in particular its cooling unit, in order to provide the liquid carbon dioxide to the at least one consumer at a temperature in the target temperature range, even if the temperature has increased above the target temperature range during an inflow of the liquid carbon dioxide via a pipeline (6) between the carbon dioxide buffer storage (4) and the carbon dioxide recooler (5).

14. Plant according to one of claims 1 to 13, characterized in that a / the pipeline (6) between the carbon dioxide buffer storage (4) and the carbon dioxide recooler (5) is substantially longer than pipelines (6) between other components of the system.

15. Plant according to one of claims 1 to 16, characterized in thatthe carbon dioxide recooler (5), if desired, together with the at least one consumer on the one hand and the carbon dioxide buffer storage (4) on the other hand are arranged in different buildings or rooms, for example of a motor vehicle manufacturing plant.

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