Fire protection systems and methods for enclosed structures

Abstract

A fire protection system and method for an enclosed enclosure, comprising: an inert reagent supply source configured to release an inert reagent after the release of a main reagent into the enclosure; a gas detector configured to determine a gas concentration level in the enclosure; and a controller connected to the inert reagent supply source and the gas detector, and configured to regulate the release of the inert reagent into the enclosure based at least in part on the gas concentration level.

Description

[0001] This application is a divisional application of the invention patent application filed on December 20, 2017, with application number 201780078692.3 (international application number PCT / US2017 / 067641) and entitled "Fire Protection System for Enclosed Bodies and Fire Protection Method for Enclosed Bodies".

[0002] Cross-reference of related applications

[0003] This application is an international patent application that claims the benefit of priority to U.S. Application Serial No. 62 / 436,691, filed December 20, 2016, the text and drawings of which are incorporated herein by reference in their entirety. Technical Field

[0004] The currently disclosed implementation schemes generally involve fire protection systems, and more specifically, a fire protection system and method for enclosed spaces. Background Technology

[0005] Gaseous agent total flooding fire protection systems involve releasing extinguishing agents to extinguish fires and providing protection for a minimum period of time within the design scope, such as a period sufficient to allow trained personnel to respond, often referred to as the "hold-off time." Maintaining the extinguishing atmosphere prevents reignition during the hold-off time. However, the concentration of the extinguishing agent decreases over time due to leakage from the enclosure and the introduction of air from outside the enclosure. To maintain the extinguishing atmosphere, some fire protection applications require extended periods of fire protection within the enclosure beyond the initial hold-off time. Some systems introduce a secondary supply of extinguishing agent into the enclosure in an attempt to compensate for agent loss through leakage and maintain the agent concentration throughout the enclosure at or above the minimum required level for the desired duration.

[0006] However, such systems may not be effective due to insufficient turbulence in the room for mixing gases, and / or the reduced emission rate as the supply becomes depleted may fall below the leakage rate of the enclosure, resulting in a relatively unpredictable atmosphere within the enclosure. Furthermore, reagent concentrations may drop below the minimum required levels without indication or warning.

[0007] Therefore, there is a need in the art for an effective and automatic fire protection system and method for maintaining a fire-extinguishing atmosphere in an enclosed space. Summary of the Invention

[0008] According to one embodiment of this disclosure, a fire protection system for an enclosed enclosure is provided. The fire protection system includes: an inert reagent supply source configured to release an inert reagent after the release of a main reagent into the enclosed enclosure; a gas detector configured to determine a gas concentration level in the enclosed enclosure; and a controller connected to the inert reagent supply source and the gas detector, and configured to regulate the release of the inert reagent into the enclosed enclosure based at least in part on the gas concentration level.

[0009] The system may further include a main reagent supply source configured to discharge the main reagent into the enclosure. The gas detector may be an oxygen level detector configured to determine the oxygen concentration level in the enclosure. The controller may be configured to initiate the discharge of the inert reagent when the oxygen concentration level exceeds a predetermined oxygen concentration level threshold. The predetermined oxygen concentration level threshold may be between 4% and 20%. The controller may be configured to regulate the discharge of the inert reagent for a predetermined holding time. The inert reagent may include nitrogen. A second gas detector may be configured to detect the presence of combustible gas in the enclosure. The inert reagent supply source may include at least one discharge valve. The system may further include a release unit configured to receive a release signal from the controller and apply pressure to the at least one discharge valve when the inert reagent is discharged.

[0010] According to one embodiment of this disclosure, a fireproofing method for an enclosed enclosure is provided. The method includes: releasing a primary reagent into the enclosed enclosure; determining a gas concentration level in the enclosed enclosure; and releasing an inert reagent into the enclosed enclosure when the gas concentration level is determined to be greater than a predetermined gas concentration threshold.

[0011] The main reagent can be discharged using a main reagent supply source, and the inert reagent can be discharged using an inert reagent supply source. The inert reagent supply source may include at least one discharge valve. The method may further include sending a signal to the release unit and pressurizing the discharge valve to discharge the inert reagent. Determining the gas concentration level may include determining the oxygen concentration level in the enclosure. The inert reagent may be discharged into the enclosure when the oxygen concentration level is determined to be greater than a predetermined oxygen concentration threshold. The predetermined oxygen concentration threshold may be between 4% and 20%. The method may further include regulating the discharge of the inert reagent into the enclosure for a predetermined holding time. The inert reagent may include nitrogen. The method may further include detecting the presence of combustible gas in the enclosure. Attached Figure Description

[0012] The embodiments and other features, advantages, and disclosures contained herein, as well as the ways in which they can be obtained, will become apparent and will provide a better understanding of this disclosure by referring to the following description of various exemplary embodiments of the disclosure taken in conjunction with the accompanying drawings: Figure 1 This is a schematic diagram of a fire protection system according to one embodiment of this disclosure; Figure 2 This is a schematic diagram of a fire protection system according to one embodiment of this disclosure; Figure 3 This is a schematic diagram of a fire protection system according to one embodiment of this disclosure; Figure 4 This is a schematic diagram of a fire protection system according to one embodiment of this disclosure; and Figure 5 A fire prevention method according to one embodiment of the present disclosure is shown. Detailed Implementation

[0013] For the purpose of facilitating understanding of the principles of this disclosure, reference will now be made to embodiments illustrated in the accompanying drawings, and these embodiments will be described using specific language. However, it should be understood that this is not intended to limit the scope of this disclosure.

[0014] Now for reference Figure 1 The figure shows a schematic representation of an enclosure 10 protected by a fire protection system 100 constructed according to one embodiment of the present disclosure. As shown, the enclosure 10 of one embodiment includes leakage openings, including, for example, an upper leakage opening 15 and a lower leakage opening 17. Those skilled in the art will readily understand that leakage openings in such an enclosure may take the form of vents or ducts or unsealed openings associated with doors or windows. The enclosure 10 also includes an HVAC blower 19 for circulating air throughout the enclosure 10 via a ventilation system 21.

[0015] According to applicable NFPA specifications and regulations (i.e., Annex C of NFPA 2001 and Annex E of ISO 14520 a), the enclosure 10 has a defined holding time, which is the period of time required for the reagent concentration to decrease to a specified level (or below). For example, the holding time of a given enclosure may be equal to 10 minutes to provide sufficient time for firefighters to arrive. The controller 16 is configured to regulate the discharge of the inert reagent 14 within the predetermined holding time. In one embodiment, the predetermined holding time may be between 5 minutes and 30 minutes, and in another embodiment, the predetermined holding time may be between 8 minutes and 12 minutes.

[0016] One embodiment of the fire protection system 100 includes an inert agent supply source 12 configured to release an inert agent 14 into an enclosure 10. In one embodiment, the inert agent 14 comprises nitrogen. In one embodiment, the inert agent 14 comprises argon. In one or more embodiments, the inert agent 14 is any inert gaseous agent comprising nitrogen, argon, carbon dioxide, and / or any mixture comprising one or more of these gases. In one embodiment, the fire protection system 100 includes a main agent supply source 30 configured to release a main agent 20 into the enclosure 10. The main agent 20 of one or more embodiments is selected from a variety of commercially available gaseous agents with broad properties, including (as a non-limiting example) HFC-227e, HFC-125, FK-5-1-12, and IG-541. Other known extinguishing agents may be used without departing from the scope of this subject matter disclosure.

[0017] The main reagent supply source 30 includes or is connected to the piping system 130. In one embodiment, the inert reagent supply source 12 also includes or is connected to the piping system 130. The piping system 130 terminates at or is otherwise connected to one or more drain valves 24. In one embodiment, the drain valve 24 is a balanced piston valve. In an embodiment not shown, the inert reagent supply source 12 includes or is connected to the piping system and / or to one or more drain valves 24 separate from the piping system 130.

[0018] Each of the inert reagent supply source 12 and the main reagent supply source 30 can take the form of a single reagent supply reservoir or container, such as Figure 1 As shown. Alternatively, each of the inert reagent supply source 12 and the main reagent supply source 30 may include multiple reagent supply reservoirs. These reagent supply reservoirs may be connected to a manifold, allowing gaseous reagents to be distributed via a piping system 130 associated with the manifold to nozzles at multiple locations within the protected enclosure.

[0019] The fire protection system 100 also includes a controller 16 connected to or otherwise communicating with an inert reagent supply source 12, and in one embodiment, connected to or otherwise communicating with a main reagent supply source 30. In one embodiment, the controller 16 is configured to discharge inert reagent 14 from the inert reagent supply source 12 after the main reagent 20 has been discharged into the enclosure 10. The controller 16 is also connected to or otherwise communicates with a gas detector 18. The gas detector 18 is configured to determine the gas concentration level in the enclosure 10. In one embodiment, the gas detector 18 is an oxygen level detector configured to determine the oxygen concentration level in the enclosure 10. One embodiment of the oxygen level detector is an oxygen sensor. Those skilled in the art will recognize that various components and processes can be used to determine the gas or oxygen level within the enclosure 10, and such components and processes form part of this disclosure.

[0020] The controller 16 is configured to regulate the emission of inert reagent 14 into the enclosure 10 based at least in part on the gas concentration level. In one embodiment, the controller 16 is configured to initiate the emission of inert reagent 14 when the oxygen concentration level exceeds a predetermined oxygen concentration threshold. The predetermined oxygen concentration level threshold is between 4% and 20% in one embodiment, between 10% and 20% in another embodiment, and between 13% and 15% in yet another embodiment.

[0021] In one embodiment, the controller 16 includes a second gas detector 22 configured to detect the presence of a combustible gas in the enclosure 10. In this embodiment, the second gas detector 22 is configured to analyze detectable combustible gases in the enclosure and send this information to the controller 16.

[0022] The fire protection system 100 also includes a release unit 26. The controller 16 transmits a release signal to the release unit 26 to initiate the release of the inert agent 14. In one embodiment, the release signal is a 24-volt signal. Upon receiving the release signal, the release unit 26 sends pneumatic pressure to one or more release valves 24. The release valves 24 release the inert agent 14 upon receiving pneumatic pressure from the release unit 26. The release valves 24 include one or more balanced piston valves configured, in one embodiment, to release the inert agent 14 upon receiving at least 8 bar of pneumatic pressure.

[0023] The controller 16 may regulate or otherwise control the emission of inert reagent 14 and / or main reagent 20 via the piping system 30 and / or one or more discharge valves 24 in response to signals received from smoke detector 114, gas detector 18, second gas detector 22 and / or another local or remote signal source. Any of these links or connections may be wireless or hardwired.

[0024] Now for reference Figure 5 And continue to refer to Figures 1 to 4 A fire protection method 200 for enclosed enclosure 10 is provided. (Reference) Figure 1 The main reagent supply source 30 contains an initial amount of gaseous reagent sufficient to achieve a predetermined initial concentration level of the gaseous reagent in the enclosure 10 within the holding time. The inert reagent supply source 12 contains an amount of inert reagent 14 sufficient to restore the concentration of the gaseous reagent in the enclosure 10 to the predetermined initial level, thereby extending the fire resistance of the enclosure 10 beyond the holding time of the enclosure. The controller 16 can be adapted and configured to detect real-time changes in the leakage characteristics of the enclosure 10 (e.g., by detecting an open window sensor) to ensure changes in the emission profile of the inert reagent supply source 12, particularly at the upper boundary of the enclosure.

[0025] Figure 5 Method 200 includes the step of discharging the main reagent 20 into the enclosure 10 at step 210. (See reference) Figure 2 When the main reagent supply source 30 of the fire protection system 100 discharges a certain amount of main reagent 20 into the enclosure 10, a sufficient amount of gaseous reagent is present in the enclosure to achieve a predetermined initial concentration level of 100% of the MDC of the enclosure 10. After this initial discharge, a relatively homogeneous mixture of reagent and air remains within the enclosure 10 for a period of time, preferably equal to the rated holding time of the enclosure. However, the density of the reagent / air mixture in the enclosure 10 is greater than the density of the air surrounding the enclosure 10. This difference applies a positive hydrostatic pressure at the lower boundary of the enclosure 10, thereby forcing the air / reagent mixture to flow out of the enclosure 10 through the available lower leak opening 17. This leakage creates a negative pressure differential at the upper boundary of the enclosure 10. Since the volume of the enclosure 10 is fixed, when the main reagent 20 leaks from the lower leak opening 17, an equal amount of air from outside the enclosure enters the upper leak opening 15. Therefore, the concentration of the main reagent 20 within the enclosure 10 decreases over time.

[0026] More specifically, such as Figure 3As shown, a specific time period has elapsed after the main reagent 20 is emitted. The concentration of the main reagent 20 in the upper portion of the enclosure 10 has decreased. As a non-limiting example, the concentration of the main reagent 20 in the enclosure 10 has decreased to approximately 85% of the MDC at a height h1 of the enclosure, which is the height of the protected asset 11.

[0027] Figure 5 Method 200 includes the step of determining the gas concentration level (such as the oxygen concentration level in one embodiment) in the enclosure 10 at step 212. Figure 3 In the illustrated embodiment, the gas or oxygen concentration level is below a predetermined gas or oxygen concentration threshold. Therefore, the protective atmosphere within the enclosure 10 is considered insufficient according to applicable fire safety standards. Remedial measures are required to restore the concentration of the gaseous reagent to the initial predetermined level.

[0028] Figure 5 Method 200 further includes the step of releasing inert reagent 14 into the enclosure 10 at step 214 when it is determined that the gas concentration level is greater than a predetermined gas concentration threshold. Figure 4 This is a diagram of the protected enclosure 10 when the inert reagent supply source 12 discharges inert reagent 14 into the enclosure 10, sufficient to restore the concentration of gaseous reagent in the enclosure 10 to 100% of the predetermined initial level of MDC.

[0029] The fire protection system 100 and method 200 disclosed herein provide automated means for detecting and / or determining the current state of the extinguishing atmosphere within the enclosed space 10. Furthermore, the fire protection system 100 and method 200 provide the ability to automatically increase or replenish reagent concentration levels to prevent ignition.

[0030] Although the invention has been shown and described in detail in the accompanying drawings and the foregoing description, the drawings and description are to be regarded as illustrative rather than restrictive in nature, and it should be understood that only certain embodiments have been shown and described, and it is intended to protect all variations and modifications within the spirit of the invention.

Claims

1. A fire protection system for enclosed spaces, comprising: An inert reagent supply source, the inert reagent supply source being configured to release an inert reagent after releasing a main reagent within the enclosure; A gas detector configured to determine the gas concentration level in the enclosure; as well as A controller, connected to the inert reagent supply source and the gas detector, is configured to regulate the emission of the inert reagent into the enclosure based at least in part on the gas concentration level; The gas detector is an oxygen level detector, which is configured to determine the oxygen concentration level in the enclosure. The controller is configured to initiate the release of the inert reagent when the oxygen concentration level exceeds a predetermined oxygen concentration level threshold.

2. The system of claim 1, further comprising a main reagent supply source configured to discharge the main reagent within the enclosure.

3. The system of claim 1, wherein the predetermined oxygen concentration level threshold is between 4% and 20%.

4. The system of claim 1, wherein the controller is configured to regulate the discharge of the inert reagent within a predetermined holding time.

5. The system according to claim 1, wherein the inert reagent comprises nitrogen.

6. The system of claim 1, further comprising a second gas detector configured to detect the presence of a combustible gas in the enclosure.

7. The system of claim 1, wherein the inert reagent supply source comprises at least one discharge valve.

8. The system of claim 7, further comprising a release unit configured to receive a release signal from the controller and to apply pressure to the at least one discharge valve when discharging the inert reagent.

9. A fireproofing method for an enclosed structure, the method comprising: The main reagent is discharged into the enclosed body; Determine the gas concentration level in the enclosed body; as well as An inert reagent is released into the enclosure when the gas concentration level is determined to be greater than a predetermined gas concentration threshold. Determining the gas concentration level includes determining the oxygen concentration level in the enclosed body; The inert reagent is released into the enclosure when the oxygen concentration level is determined to be greater than a predetermined oxygen concentration threshold.

10. The method of claim 9, wherein the main reagent is discharged using a main reagent supply source, and the inert reagent is discharged using an inert reagent supply source.

11. The method of claim 10, wherein the inert reagent supply source comprises at least one discharge valve.

12. The method of claim 11, further comprising: Send a signal to the release unit; as well as The discharge valve is pressurized to discharge the inert reagent.

13. The method of claim 9, wherein the predetermined oxygen concentration threshold is between 4% and 20%.

14. The method of claim 9, further comprising adjusting the discharge of the inert reagent into the enclosure for a predetermined holding time.

15. The method of claim 9, wherein the inert reagent comprises nitrogen.

16. The method of claim 9, further comprising detecting the presence of combustible gas in the enclosure.

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