Method of operating a cooling system and cooling system

• US 20100251737A1
• Filed: 03/05/2010
• Published: 10/07/2010
• Est. Priority Date: 03/05/2009
• Status: Active Grant

• Current Assignee: Airbus Operations GmbH (Airbus SE)
• Original Assignee: Airbus Operations GmbH (Airbus SE)
• Inventors: Roering, Sebastian
• Granted Patent: US 8,713,950 B2
• Time in Patent Office: Days
• US Class Current: 62/115
• CPC Class Codes: B64D 13/06 the air being conditioned pressurising B64D13/02
• CPC Class Codes: B64D 2013/0674 comprising liquid subsystems
• CPC Class Codes: F25B 2309/06 Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant
• CPC Class Codes: F25D 17/02 for circulating liquids, e.g. brine
• CPC Class Codes: F28F 2265/18 for removing contaminants, e.g. for degassing
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

In a method of operating a cooling system (10) that is suitable in particular for cooling food on board an aircraft, cooling energy is produced by means of a refrigerating device (12). The cooling energy produced by the refrigerating device (12) is supplied to at least one cooling station (14) by means of a cooling circuit (16), circulating in which is a refrigerant, which upon release of its cooling energy to the at least one cooling station (14) is converted from the liquid to the gaseous state and is then converted back to the liquid state by means of corresponding pressure- and temperature control in the cooling circuit (16). Upon transfer of the cooling system (10) to its state of rest, a control valve (44) disposed in the cooling circuit (16) is controlled in such a way that a desired operating pressure (p_B) arises in the cooling circuit (16) downstream of the control valve (44). Refrigerant cooled by the refrigerating device (12) is received in a reservoir (30) disposed upstream of the control valve (44) in the cooling circuit (16).

Claims

1. Method of operating a cooling system (10) that is suitable in particular for cooling food on board an aircraft, comprising the steps:

producing cooling energy by means of a refrigerating device (12) and

supplying the cooling energy produced by the refrigerating device (12) to at least one cooling station (14) by means of a cooling circuit (16), circulating in which is a refrigerant, which upon release of its cooling energy to the at least one cooling station (14) is converted from the liquid to the gaseous state and is then converted back to the liquid state by means of corresponding pressure- and temperature control in the cooling circuit (16),

characterized in that upon transfer of the cooling system (10) to its state of rest a control valve (44) disposed in the cooling circuit (16) is controlled in such a way that a desired operating pressure (p_B) arises in the cooling circuit (16) is downstream of the control valve (44) and that refrigerant cooled by the refrigerating device (12) is received in a reservoir (30) disposed upstream of the control valve (44) in the cooling circuit (16).

2. Method according to claim 1,

characterized in that the operation of the refrigerating device (12) is controlled in such a way that a desired fraction of the refrigerant upon being received in the reservoir (30) is in the liquid state.

3. Method according to claim 1,

characterized in that the backflow of refrigerant from the reservoir (30) into a region of the cooling circuit (16) lying upstream of the reservoir (30) is prevented by means of a valve (46) disposed upstream of the reservoir (30) in the cooling circuit (16).

4. Method according to claim 1,

characterized in that a conveying device (28) for conveying the refrigerant through the cooling circuit (16) and/or the refrigerating device (12) is/are switched off upon achievement of a desired refrigerant level in the reservoir (30) and/or a desired refrigerant pressure/refrigerant temperature ratio in a heat exchanger (18) in the form of a condenser, which is devised to transfer the cooling energy produced by the refrigerating device (12) to the refrigerant circulating in the cooling circuit (16).

5. Method according to claim 1,

characterized in that the cooling circuit (16) is filled with refrigerant in the state of rest of the cooling system (10) through a filling line (48) connected to the reservoir (30).

6. Method according to claim 1,

characterized in that the cooling system (10) is vented by corresponding control of a vent valve (54) disposed in a vent line (52) if an air entrapment is detected during operation of the cooling system (10).

7. Cooling system (10), in particular for cooling food on board an aircraft, comprising:

a refrigerating device (12) and

a cooling circuit (16), which is devised to supply cooling energy produced by the refrigerating device (12) to at least one cooling station (14),

wherein a refrigerant circulating in the cooling circuit (16) is so selected that upon release of its cooling energy to the at least one cooling station (14) it is convertible from the liquid to the gaseous state and is then convertible back to the liquid state by means of corresponding pressure- and temperature control in the cooling circuit (16),

characterized by a control unit (58), which is devised upon transfer of the cooling system (10) to its state of rest to control a control valve (44) disposed in the cooling circuit (16) in such a way that a desired operating pressure (p_B) arises in the cooling circuit (16) downstream of the control valve (44), and by a reservoir (30), which is disposed upstream of the control valve (44) in the cooling circuit (16) and is devised to receive refrigerant cooled by the refrigerating device (12).

8. Cooling system according to claim 7,

characterized in that the control unit (58) is devised to control the operation of the refrigerating device (12) in such a way that a desired fraction of the refrigerant upon being received in the reservoir (30) is in the liquid state.

9. Cooling system according to claim 7,

characterized by a valve (46), which is disposed upstream of the reservoir (30) in the cooling circuit (16) and is devised to prevent the backflow of refrigerant from the reservoir (30) into a region of the cooling circuit (16) lying upstream of the reservoir (30).

10. Cooling system according to claim 7,

characterized in that the control unit (58) is devised to switch off a conveying device (28) for conveying the refrigerant through the cooling circuit (16) and/or the refrigerating device (12) upon achievement of a desired refrigerant level in the reservoir (30) and/or a desired refrigerant pressure/refrigerant temperature ratio in a heat exchanger (18) in the form of a condenser, which is devised to transfer the cooling energy produced by the refrigerating device (12) to the refrigerant circulating in the cooling circuit (16).

11. Cooling system according to claim 7,

characterized by a filling line (48), which is connected to the reservoir (30) and through which the cooling circuit (16) is fillable with refrigerant in the state of rest of the cooling system (10).

12. Cooling system according to claim 7,

characterized in that the control unit (58) is devised to control a vent valve (54) disposed in a vent line (52) in such a way that the cooling system (10) is vented if an air entrapment is detected during operation of the cooling system (10).

13. Cooling system according to claim 12,

characterized in that the vent line (52) is connected to an under-cooled region (56) of a heat exchanger (18) in the form of a condenser, which is devised to transfer the cooling energy produced by the refrigerating device (12) to the refrigerant circulating in the cooling circuit (16).