Method and device for preventing and/or extinguishing fires in enclosed spaces

• US 20090014187A1
• Filed: 07/14/2008
• Published: 01/15/2009
• Est. Priority Date: 07/13/2007
• Status: Active Grant

• Current Assignee: Amrona AG
• Original Assignee: Amrona AG
• Inventors: Wagner, Ernst-Werner
• Granted Patent: US 8,602,119 B2
• Time in Patent Office: Days
• US Class Current: 169/46
• CPC Class Codes: A62C 3/004 for freezing warehouses and storages
• CPC Class Codes: A62C 99/0018 using gases or vapours that do not support combustion, e.g. steam, carbon dioxide
• CPC Class Codes: F24F 11/33 to fire, excessive heat or smoke

Abstract

The invention relates to a preventing and extinguishing fires in enclosed spaces in which the internal air atmosphere is not permitted to exceed a predefined temperature value. In order not to have to increase the cooling capacity of an air conditioning system when inert gas is added to the internal air atmosphere to set or maintain a specific inertization level within an enclosed space, a system for the regulated discharging of inert gas into same is provided. The system includes a container for the provision and storage of the inert gas in liquified form, and a vaporizer connected to the container for vaporizing at least a portion of the inert gas and discharging same into the internal air atmosphere of the enclosed space. The vaporizer thereby directly or indirectly extracts the heat energy needed to vaporize the liquid inert gas from the internal air atmosphere of the enclosed space.

Claims

1. A method for preventing fires and extinguishing fires in an enclosed space in which an internal air atmosphere is not permitted to exceed a predefined temperature value, comprising:

providing a liquefied inert gas, in particular nitrogen, in a container;

supplying at least a portion of the provided inert gas to a vaporizer;

vaporizing said at least portion of the provided inert gas in same; and

supplying a regulated amount of the inert gas vaporized in the vaporizer to the internal air atmosphere of the enclosed space such that an oxygen content in the atmosphere of the enclosed space one of drops to a specific inertization level and is maintained at same or is maintained at a specific, preset inertization level,

wherein a heat energy needed to vaporize the liquid inert gas in the vaporizer is extracted from the internal air atmosphere of the enclosed space.

2. The method according to claim 1, wherein the inert gas provided is vaporized within the enclosed space, and wherein the inert gas is supplied in liquid form to the vaporizer disposed within said space prior to the step of vaporizing.

3. The method according to claim 1, wherein the inert gas provided is vaporized external the enclosed space, and wherein at least a portion of the heat energy needed to vaporize the inert gas is extracted from the internal air atmosphere of the enclosed space by heat conduction.

4. The method according to claim 3, wherein an adjustable amount of the heat energy extracted from the internal air atmosphere of the enclosed space needed to vaporize the inert gas is regulated by setting a heat conductivity of a heat conductor used to extract the required amount of energy as a function of an actual current temperature within the enclosed space and/or a predefinable target temperature.

5. The method according to claim 3, wherein a unit cooler is used to vaporize the at least portion of the inert gas provided, and wherein the method further comprises:

supplying air from the internal air atmosphere of the enclosed space from the vaporizer or a heat exchanger allocated to said vaporizer, as heated air, in a regulated manner, at least during the vaporization of the inert gas;

providing the heat energy needed to vaporize the inert gas from at least partly extracting same by heat conduction from the air supplied by the vaporizer or the heat exchanger as heated air, whereby the air supplied as heated air cools; and

feeding the cooled air back again into space.

6. The method according to claim 5, wherein an amount of the air supplied as heated air to the vaporizer or the heat exchanger is adjustable as a function of the actual current temperature within the enclosed space and/or a predefinable target temperature.

7. The method according to claim 6, wherein the supplying the regulated amount of inert gas step further comprises:

measuring the oxygen content in the enclosed space; and

supplying the inert gas vaporized in the vaporizer as a function of the measured oxygen value of the internal air atmosphere of the enclosed space in order to maintain the oxygen content in the atmosphere of the enclosed space at a specific inertization level.

8. The method according to claim 7,

wherein the specific inertization level is a basic inertization level, and

wherein after the supplying the regulated amount of inert gas step, in the event of a fire or when otherwise needed, the oxygen content in the internal air atmosphere is further lowered to a specific full inertization level by the regulated supplying of inert gas into the internal air atmosphere.

9. The method according to claim 8, wherein a detector for fire characteristics identifies whether a fire has broken out in the enclosed space.

10. The method according to claim 9, wherein the lowering to the full inertization level in the supplying the regulated amount of inert gas step, is subject to a fire characteristic value measured by the detector.

11. The method according to claim 8, wherein the lowering to the full inertization level step is subject to the merchandise stored in the enclosed space, and in particular its ignition behavior.

12. The method according to claim 11, wherein the inert gas supplied is provided in the container, preferably configured as a cooling tank and vaporized with the vaporizer.

13. A device for for preventing fires and extinguishing fires in an enclosed space in which an internal air atmosphere is not permitted to exceed a predefined temperature value, comprising:

an oxygen-measuring mechanism for measuring an oxygen content in the internal air atmosphere of the enclosed space;

a system for a regulated discharging of inert gas into the internal air atmosphere of the enclosed space,

wherein the system comprises;

a container preferably configured as a cooling tank for provision and storage of the inert gas in liquefied form, and

a vaporizer connected to said container for vaporizing at least a portion of the inert gas provided in the container and discharging the vaporized inert gas into the internal air atmosphere of the enclosed space; and

a controller designed to control the system providing the regulated discharging of the inert gas subject to the measured oxygen content such that the oxygen content in the atmosphere of the enclosed space either one of drops to a specific inertization level or is maintained at the same level or is maintained at a specific preset inertization level,

wherein the vaporizer is configured to extract heat energy needed to vaporize the fluid inert gas from the internal air atmosphere of the enclosed space.

14. The device according to claim 13, wherein the vaporizer is a unit cooler disposed within the enclosed space.

15. The device according to claim 13, wherein the vaporizer is a unit cooler disposed external the enclosed space, and wherein the system for the regulated discharging of inert gas into the internal air atmosphere of the enclosed space further comprises a heat exchange device which provides heat transfer from the internal air atmosphere of the enclosed space to the inert gas to be vaporized in the vaporizer.

16. The device according to claim 15, further comprising:

a temperature-measuring mechanism for measuring the temperature of the internal air atmosphere of the enclosed space, and

wherein the heat exchange device comprises a heat exchanger to transfer heat energy from the internal air atmosphere to the inert gas to be vaporized in the vaporizers, an efficiency ratio of the same being adjustable in terms of the first law of thermodynamics by the controller as a function of the measured temperature and/or a predefinable target temperature.

17. The device according to claim 15, wherein the vaporizer is a unit cooler, and wherein the inert gas to be supplied to the enclosed space is used as a medium to be heated and a portion of the air from the internal air atmosphere is used as a medium to be cooled in the heat exchange device.

18. The device according to claim 17,

wherein the heat exchange device is connected to the enclosed space by means of an air duct system for the supplying and draining of air from the internal air atmosphere of the enclosed space, and

wherein the air duct system comprises at least one hot air duct and at least one cold air duct of an air conditioning system used to air condition the enclosed space.

19. The device according to claim 18, further comprising:

a temperature-measuring mechanism to measure the temperature of the internal air atmosphere within the enclosed space, and wherein the controller is designed to set an amount of air supplied to the vaporizer as a medium to be cooled as a function of the measured temperature and/or a predefinable target temperature.

20. The device according to claim 19, wherein the heat exchange device is a component of an air conditioning system used to air condition the enclosed space.

21. The device according to claim 20, wherein the air conditioning system comprises a heat exchanger through which a portion of the air from the internal air atmosphere is routed in order to transfer thermal energy from the air to a cooling medium, and wherein the heat exchanger of the air conditioning system is connected upstream or downstream of the heat exchanger associated with the vaporizer.

22. The device according to claim 21, further comprising:

a fire detection device to measure a fire characteristic in the internal air atmosphere of the enclosed space.

23. The device according to claim 22, wherein the device is used as a fire prevention device for an enclosed cold storage area, an IT room or similar space in which the internal air atmosphere of same is not permitted to exceed a specific temperature value.

24. The device according to claim 22, wherein the device is used as a fire prevention device for an enclosed switchgear cabinet or similar construction in which the internal air atmosphere of same is not permitted to exceed a specific temperature value.