Gas turbine fire detection system and related method including a cooling system upstream of a suction-type smoke detector

Abstract

A fire detection system for a gas turbine system including fire risk zones is provided. The system includes pipe intake ports adjacent to each of the fire risk zones within the gas turbine system housing, and a manifold that fluidly communicates with the pipe intake ports. A temperature sensor is positioned in the manifold upstream of a cooling system. The cooling system lowers the temperature of the gas flow in the manifold, enabling the use of a suction smoke detector. A suction smoke detector downstream of the cooling system draws in the gas flow and detects smoke in the gas flow. The controller generates a first alarm in response to the temperature sensor detecting a gas flow temperature exceeding a temperature threshold, or a second alarm in response to the suction smoke detector detecting smoke in the gas flow.

Description

Technical Field

[0001] The present disclosure generally relates to gas turbine systems, and more particularly, to a system for detecting a fire inside an enclosure of a gas turbine system, and related methods.

Background Art

[0002] A gas turbine system includes a compressor section, a combustion section, and a turbine section (e.g., an expansion turbine). Compressed air is supplied from the compressor section to the combustion section. The air entering the combustor(s) in the combustion section is mixed with fuel and burned. The hot combustion gases flow from the combustion section to the turbine section, driving the gas turbine to generate electricity. Gas turbine systems, such as those used for power generation, are generally housed within an enclosure. A typical enclosure includes four side walls surrounding the gas turbine system, and a roof or upper wall fixed to the four side walls around the perimeter. Thus, the roof and side walls generally form a hollow rectangular enclosure.

[0003] Fires within gas turbine casings require special consideration due to safety concerns. Detecting fires in proximity to fire risk zones such as fuel supply areas or combustors is preferable for early detection and corrective action, and combustors typically include multiple combustors. Suction smoke detectors detect smoke using a turbidimeter that detects smoke particles suspended in the gas by continuously drawing in gas (e.g., air) through a pipe(s) and detecting the scattered light within a sensing chamber through which the gas passes. Suction smoke detectors can also detect smoke before it becomes visible to the human eye by using, for example, infrared or laser light within the sensing chamber. Suction smoke detectors are advantageous because they are more sensitive and allow for earlier fire detection compared to other devices such as thermal detectors, flame detectors, optical smoke detectors, or ionization smoke detectors. During operation, the ambient temperature inside the casing is in the range of 65-120°C (approximately 150-250°F) or higher. However, suction smoke detectors have an intake air temperature limit of, for example, approximately 60°C (approximately 140°F). Therefore, they cannot be used to detect fires inside the gas turbine casing. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2022-0235641 [Overview of the project]

[0005] All aspects, examples, and features described below can be combined in any technically possible way.

[0006] One aspect of the present disclosure provides a fire detection system for a gas turbine system including a plurality of fire risk zones, the fire detection system comprising: pipe intake ports adjacent to each of the plurality of fire risk zones within a housing surrounding the gas turbine system; a manifold in fluid communication with at least one of the pipe intake ports; a first temperature sensor positioned within the manifold; a cooling system downstream of the first temperature sensor within the manifold, the cooling system configured to reduce the temperature of the gas flow within the manifold; a suction smoke detector downstream of the cooling system within the manifold, the suction smoke detector configured to draw in the gas flow through the manifold and detect smoke in the gas flow; and a controller communicating with the first temperature sensor and the suction smoke detector, the controller configured to do one of the following: a) generate a first alarm in response to the first temperature sensor detecting a gas flow temperature exceeding a first temperature threshold; and b) generate a second alarm in response to the suction smoke detector detecting smoke in the gas flow.

[0007] Another aspect of the present disclosure includes any of the above-described aspects and further comprises a safety system including a valve in a manifold upstream of the cooling system and a second temperature sensor in a manifold downstream of the cooling system and upstream of a suction-type smoke detector, wherein the controller is further configured to generate a third alarm in response to the second temperature sensor detecting a gas flow temperature exceeding a second temperature threshold.

[0008] Another aspect of the present disclosure includes any of the above-described aspects, wherein the controller is further configured to close a valve and shut off a suction-type smoke detector in response to a second temperature sensor detecting a gas flow temperature exceeding a second temperature threshold.

[0009] Another aspect of the present disclosure includes any of the aspects described above, wherein the first alarm includes one of an overheat detection alarm, a pre-fire alarm, and a fire alarm.

[0010] Another aspect of the present disclosure includes any of the aspects described above, wherein the second alarm includes one of a smoke detection alarm, a pre-fire alarm, and a fire alarm.

[0011] Another aspect of the present disclosure includes any of the above-described aspects, further comprising a filter upstream of the suction-type smoke detector.

[0012] Another aspect of the present disclosure includes any of the above-described aspects, wherein the fire risk zones include areas adjacent to at least some of the combustor canisters of the gas turbine system.

[0013] Another aspect of the present disclosure includes any of the above-described aspects, wherein the fire risk zones further include areas adjacent to at least one fuel module of the gas turbine system.

[0014] Another aspect of the present disclosure includes any of the above-described aspects, wherein the manifold extends outside the housing, and the first temperature sensor, cooling system, suction-type smoke detector, and controller are located outside the housing.

[0015] Another aspect of the present disclosure includes any of the above-described aspects, wherein the manifold comprises a plurality of manifolds, each manifold having fluid communication with at least one intake port, and each comprising a first temperature sensor, a cooling system, and a suction smoke detector, and a controller communicating with each of the respective first temperature sensors and each of the respective suction smoke detectors, and the controller is configured to do one of the following: a) generate a first alarm in response to any of the first temperature sensors detecting a temperature in the gas flow within each manifold that exceeds a first temperature threshold, and b) generate a second alarm in response to any suction smoke detector detecting smoke in the gas flow within each manifold.

[0016] Another aspect of the present disclosure includes a fire detection system for a gas turbine system comprising a plurality of fire risk zones, the fire detection system comprising: pipe intake ports adjacent to each of the plurality of fire risk zones within a housing surrounding the gas turbine system; at least one manifold in fluid communication with at least one of the pipe intake ports; a first temperature sensor positioned within each manifold; a cooling system downstream of the first temperature sensor within each manifold, the cooling system configured to reduce the temperature of the gas flow within each manifold; a valve within each manifold upstream of the cooling system; and a suction smoke detector downstream of the cooling system within each manifold, the suction smoke detector through each manifold A suction smoke detector is configured to generate separate gas flows and detect smoke in each gas flow. The suction smoke detector is configured to communicate with each first temperature sensor and each first temperature sensor, wherein the controller is configured to: a) generate a first alarm in response to any first temperature sensor detecting a gas flow temperature exceeding a first temperature threshold; and b) generate a second alarm in response to any first temperature sensor detecting smoke in each gas flow. The controller is further configured to close each valve and shut off the suction smoke detector in response to a second temperature sensor detecting a gas flow in each manifold temperature exceeding a second temperature threshold.

[0017] Another aspect of the present disclosure includes any of the above-described aspects and further comprises a safety system including a second temperature sensor in each manifold downstream of each cooling system and upstream of a suction-type smoke detector, wherein the controller is further configured to generate a third alarm in response to each second temperature sensor detecting a gas flow temperature exceeding a second temperature threshold.

[0018] Another aspect of the present disclosure includes any of the above-described aspects, in each respective manifold, the valve is located downstream of the first temperature sensor.

[0019] Another aspect of the present disclosure includes any of the aspects described above, wherein the first alarm includes one of an overheat detection alarm, a fire pre-alarm, and a fire alarm, and the second alarm includes one of a smoke detection alarm, a fire pre-alarm, and a fire alarm.

[0020] Another aspect of the present disclosure includes any of the aspects described above, wherein the second alarm includes one of a smoke detection alarm, a pre-fire alarm, and a fire alarm.

[0021] Another aspect of the present disclosure includes any of the above-described aspects, further comprising a filter upstream of the suction-type smoke detector.

[0022] Another aspect of the present disclosure includes any of the above-described aspects, wherein the fire risk zones include areas adjacent to at least some of the multiple combustor canisters of the gas turbine system, areas adjacent to at least one fuel module of the gas turbine system, or both.

[0023] Another aspect relates to a method for detecting a fire in a gas turbine system including a plurality of fire risk zones, the method comprising: using a suction smoke detector to generate a gas flow into a manifold from at least one of the plurality of fire risk zones; generating a first alarm in response to a first temperature sensor in the manifold detecting a gas flow temperature exceeding a first temperature threshold; using a cooling system to cool the gas flow downstream of the first temperature sensor and upstream of the suction smoke detector; and generating a second alarm in response to the suction smoke detector detecting smoke in the gas flow.

[0024] Another aspect of the present disclosure includes any of the above-described aspects, further comprising a second temperature sensor located downstream of the cooling system and upstream of the suction-type smoke detector generating a third alarm in response to detecting a gas flow temperature exceeding a second temperature threshold.

[0025] Another aspect of the present disclosure includes any of the aspects described above, and in response to the second temperature sensor detecting a temperature of the gas flow that exceeds a second temperature threshold, closes a valve in the manifold upstream of the cooling system and shuts off the aspirating smoke detector to stop the generation of the gas flow and the detection of smoke.

[0026] Two or more aspects described in this summary section may be combined to form implementations not specifically described herein.

[0027] Details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

[0028] These and other features of the present disclosure will be more readily understood from the following detailed description of the various aspects of the present disclosure in conjunction with the accompanying drawings that illustrate various embodiments of the present disclosure.

Brief Description of the Drawings

[0029] [Figure 1] It is a schematic plan view of a gas turbine system disposed in a gas turbine housing and including a fire detection system according to an embodiment of the present disclosure. [Figure 2] It shows a schematic cross-sectional view of an end portion of a combustion section of a gas turbine system provided with a fire detection system according to an embodiment of the present disclosure. [Figure 3] It shows a schematic view of an exemplary aspirating smoke detector according to an embodiment of the present disclosure. [Figure 4] It shows a schematic cross-sectional view of an end portion of a combustion section of a gas turbine system provided with a fire detection system according to an embodiment of the present disclosure. [Figure 5] It shows a schematic cross-sectional view of an end portion of a combustion section of a gas turbine system provided with a fire detection system according to an embodiment of the present disclosure. [Figure 6]This diagram shows a schematic cross-sectional view of the end of the combustion section of a gas turbine system equipped with a fire detection system according to an embodiment of the present disclosure. [Figure 7] A flowchart illustrating a method for detecting a fire in a gas turbine system or gas turbine housing according to embodiments of this disclosure is shown. [Modes for carrying out the invention]

[0030] Please note that the drawings in this disclosure are not to scale. The drawings are intended to illustrate only typical aspects of this disclosure and should not be considered to limit the scope of this disclosure. In the drawings, similar reference numerals represent similar elements between drawings.

[0031] As a first issue, in order to clearly describe this disclosure, it is necessary to select specific terminology when referring to and describing relevant mechanical components within a gas turbine housing. Where this is done, common industry terminology is used where possible and is used in accordance with its accepted meaning. Unless otherwise specified, such terminology should be given a broad interpretation consistent with the context of this application and the appended claims. Those skilled in the art will understand that, in many cases, a particular component may be referred to using multiple different or overlapping terms. What may be described herein as a single part may include multiple components and be referred to in another context as consisting of multiple components. Conversely, what may be described herein as including multiple components may be referred to elsewhere as a single part.

[0032] Furthermore, several descriptive terms may be used periodically in this specification, and it will be useful to define these terms at the beginning of this section. These terms and their definitions are as follows, unless otherwise specified: As used herein, “downstream” and “upstream” are terms indicating the direction of a fluid flow, such as ventilation fluid through a gas turbine casing, or, for example, an air flow through a pipe. The term “downstream” corresponds to the direction of the fluid flow, and the term “upstream” refers to the direction opposite to the flow.

[0033] When an element or layer is referred to as "on top of," "engaged to," "disengaged from," "connected to," or "joined to" another element or layer, it may be directly on top of, engaged to, connected to, or joined to the other element or layer, or an intervening element or layer may exist. In contrast, when an element is referred to as "directly on top of," "directly engaged to," "directly connected to," or "directly joined to" another element or layer, an intervening element or layer may not exist. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent"). As used herein, the term "and / or" includes any and all combinations of one or more of the enumerated items relating to it.

[0034] Embodiments of the present disclosure include a fire detection system for a gas turbine system comprising a plurality of fire risk zones. The fire detection system includes pipe intake ports adjacent to each of the plurality of fire risk zones, and a manifold in fluid communication with at least one of the pipe intake ports. A first temperature sensor is positioned within the manifold. A cooling system is located downstream of the first temperature sensor within the manifold. The cooling system lowers the temperature of the gas flow within the manifold, enabling the use of a suction smoke detector. The suction smoke detector is located downstream of the cooling system, draws in the gas flow, and detects smoke in the gas flow. A controller generates a first alarm in response to the first temperature sensor detecting a gas flow temperature above a first temperature threshold, or a second alarm in response to the suction smoke detector detecting smoke in the gas flow. The system enables the use of a suction smoke detector for a gas turbine system by providing a cooling system for the gas flow. By using both an upstream temperature sensor and a suction smoke detector, the system provides earlier fire detection than would otherwise be possible, thereby improving the safety of the gas turbine system.

[0035] Figure 1 shows a schematic plan view of a gas turbine system 100, which is housed within a gas turbine housing 102 and includes a fire detection system 104 according to an embodiment of the present disclosure. Figure 2 shows a schematic cross-sectional view of the end of a combustor 108 of a gas turbine system 100 (hereinafter referred to as "GT system 100") equipped with a fire detection system 104 according to an embodiment of the present disclosure. In Figures 1 and 2, the GT system 100 is shown as a simple-cycle, single-shaft heavy-duty gas turbine system, but any various GT systems may be included. For illustrative purposes, the GT system 100 can be thought of as comprising a multistage axial-flow compressor 106 having a rotating shaft (not shown). Air enters the inlet of the compressor 106, is compressed by the axial-flow compressor, and is then exhausted to the combustor 108, where a fuel such as natural gas, a liquid fuel, or a combination thereof is burned to provide high-energy combustion gases that drive the turbine 110. As shown in Figure 2, the combustor 108 may include, for example, a circular array of annular multi-cylinder combustors 112 (hereinafter, "combustor can 112"), or any other type of combustor. In the turbine 110, the energy of the hot gas is converted into work, some of which can be used to drive the compressor 106 via a rotating shaft, and the remainder can be used for useful work to drive a load such as a generator (not shown). As is understood in the art, and as schematically shown in Figure 1, a wide range of combustor fuel supply systems 114 supply fuel, such as natural gas and / or liquefied gas, to the combustor 108. The fuel supply system 114 may include any fuel module 116 (Figure 2) that is currently known or will be developed in the future. This disclosure is not limited to any one particular GT system 100 and may be implemented in connection with other turbine engines.

[0036] The gas turbine housing 102 encloses the GT system 100. The gas turbine housing 102 includes side walls 120, a top wall 122 (shown as transparent in Figure 1), and a floor 124. The GT system 100 is housed within the gas turbine housing 102. The fuel module 116 can be located inside or outside the gas turbine housing 102.

[0037] The GT system 100 may include multiple fire risk zones. As used herein, “fire risk zone” is any location where fire detection is desired. A non-exclusive list of fire risk zones in the GT system 100 may include, for example, the combustor can(s) 112 or other parts of the combustion section 108, the fuel supply system 114 including parts thereof such as the fuel module 116 and pipe joints, the exhaust area of ​​the turbine section 110, and / or other areas within the gas turbine housing 102 where fire is a concern. For illustrative purposes only, a specific combustor can 112 and / or area adjacent to at least one fuel module 116 of the fuel supply system 114 of the GT system 100 (Figure 1) is identified in the drawings as an exemplary fire risk zone.

[0038] The fire detection system 104 (hereinafter, "system 104") may include pipe intake ports 130 adjacent to each of a plurality of fire risk zones. Thus, one or more pipe intake ports 130 may be provided. The pipe intake ports 130 may include any various openings in the pipe 132 through which a gas (e.g., air) sample can be drawn into the pipe 132. For example, the pipe intake ports 130 may be small openings in the pipe 132 adjacent to a fire risk zone. As used herein, the terms "adjacent to" or "adjacent to" indicate that the pipe intake ports 130 are close enough to a particular structure constituting a desired fire risk zone to ensure that the gas drawn into them indicates a fire within or around that particular structure. The pipe 132 may be routed in any way to position the pipe intake ports 130 near fire risk zones. The pipe intake ports 130 may be arranged in any way, such as an array, for example, a circular array around a ring-shaped combustor can 112.

[0039] Manifold 136 is in fluid communication with at least one of the pipe intake ports 130. Manifold 136 may include a chamber that connects a single pipe 132 and / or multiple pipes 132 together. Manifold 136 and / or pipe(s) 132 may be any conduit capable of accommodating and passing the gas flow 140 (indicated by arrows). Manifold 136 and / or pipe(s) 132 may include rigid material conduits, such as steel pipes, which are screwed together and held in place by mounts (not shown). In non-limiting examples, manifold 136 and / or pipe(s) 132 may have outer diameters selected according to calculations of flow rate and pressure. Manifold 136 and / or pipe(s) 132 may optionally be insulated in any way to retain the heat of the gas flow 140.

[0040] It is emphasized that the “multiple fire risk zones” as used herein do not necessarily include all fire risk zones of the GT system 100 or the gas turbine housing 102. For example, it may include part or all of the combustor canister 112 and further include areas adjacent to at least one fuel module 116 of the fuel supply system 114 of the GT system 100. For example, Figures 1 and 2 show pipe intake ports 130 adjacent to only a portion of the canister combustor 112. In contrast, Figure 4 shows pipe intake ports 130 adjacent to the entire canister combustor 112, for example, using a single annular pipe 232. As described herein, pipe intake ports 130 may be provided in any number of fire risk zones, and each pipe intake port 130 may be defined by a variety of pipe arrangements.

[0041] System 104 also includes a first upstream temperature sensor 142 positioned within the manifold 136. At least a portion of the upstream temperature sensor 142 is operably positioned within the manifold 136 to measure the temperature of the gas flow 140 within the manifold 136. The upstream temperature sensor 142 may be positioned within the manifold 136 at any location downstream of the pipe intake port(s) 130 where elevated temperatures indicating a fire can be measured. For example, the upstream temperature sensor 142 can be positioned close enough to a desired fire risk zone, e.g., combustor can(s) 112, to prevent the gas flow 140 within the manifold 136 from losing heat below a level indicating the presence of a fire. The upstream temperature sensor 142 may include any form of industrial temperature sensor capable of withstanding fire-level temperatures in the gas flow 140. The upstream temperature sensor 142 may include, but is not limited to, thermocouples, resistance temperature detectors (RTDs), thermistors, and / or semiconductor-based integrated circuits. As further described herein, the upstream temperature sensor 142 is operably coupled to the controller 170 using any currently known or later developed communication system, e.g., cellular, wireless, wired, or other communication network (see dashed communication path).

[0042] System 104 includes a suction smoke detector (ASD) 150 downstream of the cooling system 164 (as described herein) in the manifold 136. The ASD 150 is configured to generate a gas flow 140 through the manifold 136 (and pipes 132, 232) and to detect smoke in the gas flow 140. Figure 3 shows a schematic plan view of an exemplary ASD 150. The ASD 150 may include a sensing chamber 154 containing a turbidimeter 156 inside, and a fan, aspirator, or other form of suction device 158 (hereinafter, "fan 158") that generates (pushes or draws in) the gas flow 140 through System 104. The fan 158 can generate sufficient negative pressure (suction) inside the pipe intake port 130, pipes 132, 232 and manifold 136 to draw in gas flow 140, i.e., one or more environmental samples (air) from each of the fire risk zones 100 of the GT system 100, through the sensing chamber 154. The required negative pressure can vary depending on many factors, but is not limited, such as the number of pipe intake ports 130 (fire risk zones), the diameter and length of pipes 132, 232 and / or manifold 136, and the number of corners or constrictions in pipes 132, 232 and / or manifold 136.

[0043] As understood in the art, the ASD150 continuously draws in a gas flow 140 (e.g., air or air containing smoke) through a manifold 136 (and pipe intake port 130) and detects smoke using a turbidimeter 156. The turbidimeter 156 detects smoke particles suspended in the gas flow 140 by detecting scattered light in a sensing chamber 154 through which the gas flow 140 passes. The ASD150 may optionally include any type of filter 160 that can remove undesirable contaminants other than those detected by the ASD150, e.g., non-smoke contaminants. The filter 160 may, for example, remove contaminants that interfere with smoke detection, e.g., particles larger than smoke particles produced by the combustion of certain fuels used in the GT system 100 (note that although the filter 160 is shown separately from the ASD150, it may alternatively be part of the ASD150).

[0044] The ASD150 may use any currently known or future-developed light source, such as infrared or laser light, within the sensing chamber 154 to detect smoke before it becomes visible to the naked eye. The ASD150 can "detect" smoke based on any user-defined accumulation level of smoke particles in the gas flow 140, such as a specific parts per million level. In response to the ASD150 detecting smoke, a signal is transmitted to the controller 170. As further described herein, the ASD150 is operably coupled to the controller 170 using any currently known or future-developed communication system, such as cellular, wireless, wired, or other communication network (see dashed communication path). Once the gas flow 140 has passed through the ASD150, it can be discharged into the atmosphere.

[0045] As described above, the ASD150 is advantageous because it is more sensitive and enables early detection of fire compared to other devices such as thermal detectors, flame detectors, optical smoke detectors, or ionized smoke detectors. However, a fire in the GT system 100 may generate temperatures higher than those at which the ASD150 can operate. For example, a fire can generate a gas flow temperature of over 120°C (approximately 248°F) in the gas flow 140, while the ASD150 has an intake gas temperature limit of, for example, approximately 60°C (approximately 140°F). To enable the use of the ASD150 for fire detection in the GT system 100, the system 104 includes a cooling system 164 within the manifold 136 upstream of the ASD150. The cooling system 164 is also located downstream of the upstream temperature sensor 142 to avoid affecting any temperature sensing before that sensor.

[0046] The cooling system 164 is configured to reduce the temperature of the gas flow 140 in the manifold 136 to a level sufficient to allow the ASD 150 to be used for early fire detection, for example, below about 60°C (about 140°F). The cooling system 164 may include any currently known or future-developed cooling device that can reduce the temperature of the gas flow 140, such as a heat exchanger 166 including piping that allows the gas flow 140 to be in thermal communication with a coolant (not shown). The heat exchanger 166 may include a refrigeration system or other industrial cooling device that can reduce the temperature of the gas flow 140 to a level at which the ASD 150 can operate. As further described herein, the cooling system 164 is operably coupled to the controller 170 using any currently known or future-developed communication system, e.g., cellular, wireless, wired, or other communication network (see dashed communication path). Thus, the controller 170 can control the operation of the cooling system 164.

[0047] System 104 also includes a controller 170 that communicates with an upstream temperature sensor 142 and an ASD 150. The controller 170 is configured to do one of the following: a) generate a first (fire temperature) alarm in response to the upstream temperature sensor 142 detecting a temperature in the gas flow 140 that exceeds a first temperature threshold; and b) generate a second (smoke) alarm in response to the ASD 150 detecting smoke in the gas flow 140. Based on one or both alarms, any corrective actions currently known or to be developed later, e.g., passive or more definitive actions depending on the circumstances, may be taken. For example, passive corrective actions may include, but are not limited to, initiating a visual verification of the cause of the alarm, activating an audible alarm, and / or performing additional monitoring. More definitive corrective actions may include, but are not limited to, activating fire suppression and / or fire extinguishing systems (e.g., sprinklers, foam, or other fire extinguishing systems), initiating deceleration or shutdown of the GT system 100, and / or stopping the fuel supply by the fuel supply system 114. The first temperature threshold can be any user-defined temperature for detecting a fire in each fire risk zone, e.g., within the combustor can 112. In one non-limiting example, the first temperature threshold may be 120°C (approximately 248°F).

[0048] The first (high temperature) alarm can indicate a user-defined command in one of the following forms: a) an overheat detection alarm that may require passive corrective measures such as additional monitoring; b) a pre-fire alarm that may require passive corrective measures such as verification by other mechanisms such as visual inspection; and c) a fire alarm that requires more definitive corrective measures such as fire suppression or emission control, or shutdown of the GT system 100. The second (smoke) alarm can indicate a user-defined command in one of the following forms: a) a smoke detection alarm that may require passive corrective measures such as additional monitoring and / or more definitive corrective measures such as fire suppression or emission control, or shutdown of the GT system 100; b) a pre-fire alarm that may require passive corrective measures such as verification by other mechanisms such as visual inspection; and c) a fire alarm that requires more definitive corrective measures such as fire suppression or emission control, or shutdown of the GT system 100. Controller 170 is configured to interact with the overall controller (not shown) of the GT system 100, possibly to implement one of the described corrective actions.

[0049] The controller 170 may also be configured to provide corrective actions based on the occurrence of a combination of “alarm triggers,” for example, the temperature of the gas flow 140 exceeding a first temperature threshold and the ASD 150 detecting smoke in the gas flow 140. For example, when only one of the alarm triggers occurs, such as commanding a visual verification of the fire before escalating the alarm to require fire suppression or exhaust measures, passive corrective actions may be considered. Alternatively, as described above, definitive corrective actions such as fire suppression or exhaust may occur only when both fire alarm triggers occur, i.e., when the temperature of the gas flow 140 exceeds a first temperature threshold and the ASD 150 detects smoke in the gas flow 140. In addition, the controller 170 may take different corrective actions based on the degree or scale of one or both alarm triggers, i.e., the degree of temperature measured by the upstream temperature sensor 142 compared to the normal operating temperature of the gas flow 140, or the amount of smoke detected by the ASD 150.

[0050] System 104 may also optionally include a safety system 180 configured to protect the ASD 150, among other structures. The safety system 180 may include a valve 182 in the manifold 136 upstream of the cooling system 164. The valve 182 may include any type of industrial valve that can close the manifold 136 to stop the gas flow 140 to the cooling system 164 and the ASD 150. The safety system 180 may also include a second downstream temperature sensor 184 in the manifold 136 downstream of the cooling system 164 and upstream of the ASD 150. The downstream temperature sensor 184 has at least a portion of it that is operably positioned to measure the temperature of the gas flow 140 in the manifold 136. The downstream temperature sensor 184 may be positioned in the manifold 136 at any position downstream of the cooling system 164 and upstream of the ASD 150. In this way, the downstream temperature sensor 184 can ensure that the temperature of the gas flow 140 flowing into the ASD 150 does not exceed the temperature limit of the ASD 150, for example, not exceeding approximately 60°C (approximately 140°F). The gas flow 140 may reach a temperature that could damage the ASD 150, for example, if the cooling system 164 is not functioning properly or is off, or if the valve 182 is closed.

[0051] The downstream temperature sensor 184 may include any form of industrial temperature sensor capable of withstanding the temperature of the gas flow 140. The downstream temperature sensor 184 may include, but is not limited to, thermocouples, resistance temperature detectors (RTDs), thermistors, and / or semiconductor-based integrated circuits. The downstream temperature sensor 184 is operably coupled to the controller 170 using any currently known or later developed communication system, e.g., cellular, wireless, wired, or other communication network (see dashed communication path).

[0052] With respect to the safety system 180, the controller 170 may be further configured to generate a third (ASD safety) alarm in response to the downstream temperature sensor 184 detecting that the temperature of the gas flow 140 exceeds a second temperature threshold. The second temperature threshold may be any user-defined temperature at which protection of the ASD 150 is considered to be guaranteed, e.g., about 60°C (about 140°F). The third (ASD safety) alarm may take the form of, for example, a visual or audible alarm which may prompt passive corrective action, such as manual monitoring or checking of the cooling system 164. In addition to or instead of this, the controller 170 may be further configured to close the valve 182 and / or shut off the ASD 150 in response to the second temperature sensor 184 detecting that the temperature of the gas flow 140 exceeds a second temperature threshold. In this way, the ASD 150 can be protected from excessive temperature.

[0053] System 104 can be customized for a wide variety of GT systems 100. Specifically, among other structural elements of System 104, the pipe intake port 130, manifold 136 and / or pipe 132, cooling system 164, and ASD 150 can take on various configurations for early fire detection in the GT system 100 and / or gas turbine housing 102. For example, all parts of System 104 can be scaled for GT systems 100 of different sizes. In another example, parts of System 104 can be duplicated to enable customized fire detection for different fire risk zones. In Figures 1 and 2, for example, multiple fire risk zones include areas adjacent to at least some of the multiple combustor cans 112 of the GT system 100. In Figure 4, multiple fire risk zones include areas adjacent to each combustor can 112 of the GT system 100.

[0054] Figures 5 and 6 show schematic diagrams of system 104 including duplicated components for isolating different fire risk zones (may be more) than those in Figures 1 and 2 for fire detection. In Figure 5, four fire risk zones are created, generally labeled A through D, and in Figure 6, three fire risk zones are created, generally labeled E through G. In Figure 5, fire risk zone A includes one-third of the combustor can 112, fire risk zone B includes another one-third of the combustor can 112, fire risk zone C includes the last one-third of the combustor can 112, and fire risk zone D includes a portion of the fire module 116X. In Figure 6, fire risk zone E includes the upper part of the combustor 108, for example, near some of the combustor can 112, fire risk zone F includes the upper parts of both fuel modules 116X and 116Y, and fire risk zone G includes the lower parts of both fuel modules 116X and 116Y.

[0055] In these examples, manifold 136 may include multiple manifolds 136A-D (Figure 5), 136E-G (Figure 6), each manifold 136A-G having fluid communication with at least one intake port 130 and including each first temperature sensor 142A-D (Figure 5), 142E-G (Figure 6). In Figures 5 and 6, ASD 150A-D (Figure 5) or 150E-G (Figure 6) is shown for each gas flow 140A-D (Figure 5) or 140E-G (Figure 6). In this way, each ASD 150A-D (Figure 5) or 150E-G (Figure 6) generates its respective gas flow 140A-D (Figure 5) or 140E-G (Figure 6) and detects smoke within its respective gas flow 140A-D (Figure 5) or 140E-G (Figure 6). Figures 5 and 6 show a single cooling system 164 having multiple heat exchangers 166A-D (Figure 5) or 166E-G (Figure 6). In these embodiments, each heat exchanger 166A-D (Figure 5) or 166E-G (Figure 6) can provide customized thermal reduction, for example, depending on the expected temperature of the gas flow 140A-D (Figure 5) or 140E-G (Figure 6) drawn through it. Each fire risk zone may alternatively include its own isolated cooling system 164 (see dashed line in the box labeled 164 in Figure 5) having its own heat exchanger 166, and it would presumably be recognized that each cooling system provides customized thermal reduction, for example, depending on the expected temperature of the gas flow 140A-D (Figure 5) or 140E-G (Figure 6) drawn through it.

[0056] In Figures 5 and 6, system 104 includes pipe intake ports 130 adjacent to each of the multiple fire risk zones A–G. At least one manifold 136A–D (Figure 5) or 136E–G (Figure 6) is in fluid communication with at least one of the pipe intake ports 130. First temperature sensors 142A–D (Figure 5) or 142E–G (Figure 6) are positioned upstream of valve 182 and within each manifold 136A–D (Figure 5) or 136E–G (Figure 6), as described herein. System 104 also includes a cooling system 164 (and possibly multiple cooling systems) downstream of the first temperature sensors 142A–D (Figure 5) or 142E–G (Figure 6) within each manifold 136A–D (Figure 5) or 136E–G (Figure 6). As described above, the cooling system(s) 164 are configured to reduce the temperature of the gas flows 140A-D(Figure 5) or 140E-G(Figure 6) within each manifold 136A-D(Figure 5) or 136E-G(Figure 6). The ASD150A-D(Figure 5) or 150E-G(Figure 6) are located downstream of the cooling system(s) 164(s) within each manifold 136A-D(Figure 5) or 136E-G(Figure 6). As described above, each ASD150A-G(Figures 5-6) generates the respective gas flows 140A-G(Figures 5-6) that pass through each manifold 136A-G(Figures 5-6) and is configured to detect smoke within each gas flow 140A-G(Figures 5-6).

[0057] The controller 170 communicates with each of the first temperature sensors 142A-D (Figure 5) or 142E-G (Figure 6), and each of the ASDs 150A-D (Figure 5) or 150E-G (Figure 6). During operation, the controller 170 is configured to generate either or both of the following: a) generate a first alarm in response to any first temperature sensors 142A-D (Figure 5), 142E-G (Figure 6) detecting that the temperature of the gas flows 140A-D (Figure 5), 140E-G (Figure 6) in their respective manifolds 136A-D (Figure 5), 136E-G (Figure 6) exceeds a first temperature threshold; and b) generate a second alarm in response to any suction-type smoke detectors 150A-D (Figure 5), 150E-G (Figure 6) detecting smoke in their respective gas flows 140A-D (Figure 5), 140E-G (Figure 6) in their respective manifolds 136A-D (Figure 5), 136E-G (Figure 6). As will be further described, each fire risk zone A-G may have its own first temperature threshold and smoke detection threshold.

[0058] System 104 in Figures 5 and 6 also includes safety systems (not labeled for clarity). Each safety system includes valves 182A-D (Figure 5), 182E-G (Figure 6) in each manifold 136A-D (Figure 5), 136E-G (Figure 6) upstream of each cooling system 164(or more) Here, the controller 170 is further configured to generate a third (ASD safety) alarm in response to each of the second temperature sensors 184A~D (Figure 5), 184E~G (Figure 6) detecting that the temperature of each gas flow 140A~D (Figure 5), 140E~G (Figure 6) exceeds a second temperature threshold. The controller 170 may be further configured to close each of the valves 182A~D (Figure 5), 182E~G (Figure 6) and shut off each of the ASDs 150A~D (Figure 5), 150E~G (Figure 6) in response to the second temperature sensor detecting that the temperature of each gas flow 140A~D (Figure 5), 140E~G (Figure 6) in each of the manifolds 136A~D (Figure 5), 136E~G (Figure 6) exceeds the second temperature threshold. The controller 170 can also control the cooling system 164(or more) in any way to protect the ASD150A-G.

[0059] In addition to different structures, system 104 can also implement different fire risk zones, e.g., fire risk zones A to D (Figure 5), or different temperature thresholds for different GT systems 100. More specifically, if there are two or more fire risk zones, the first temperature threshold can vary depending on the specific fire risk zone in question. For example, a fire adjacent to a combustor can 112 may have a different temperature than a fire in a fuel module 116 and require a different first temperature threshold. In this way, the first (high temperature) alarm may require a first temperature threshold of, for example, 218°C (approximately 425°F) for the fire risk zone around the combustor can 112(or more), but a different first temperature threshold of, for example, 162°C (approximately 325°F) for the fire risk zone within the fuel module(or more) 116. Different GT systems 100 of different sizes or GT systems 100 using different fuel types may require different first temperature thresholds.

[0060] Similarly, if there are two or more fire risk zones, the smoke particle concentration required for each ASD, e.g., ASD150A-D (Figure 5), to "detect" smoke and for the controller 170 to generate a second (smoke) alarm may vary depending on the specific fire risk zone. For example, a fire adjacent to the combustor can 112 may produce smoke with a lower smoke particle concentration than a fire in the fuel module 116, requiring a different smoke detection particle concentration threshold. Different GT systems 100 of different sizes or different GT systems 100 using different fuel types may require different smoke particle concentration thresholds.

[0061] Figures 5 and 6 show two embodiments of the system 104 having fire detection in two or more fire risk zones, but it is emphasized that a wide variety of alternative configurations with fire detection in numerous alternative fire risk zones are possible and are within the scope of this disclosure.

[0062] Figure 7 shows a flowchart of how system 104 operates. Although Figure 7 primarily describes a single fire risk zone, it will be recognized that the described method can be repeated for multiple fire risk zones, as described above. In process P1, system 104 generates a gas flow 140 into manifold 136 from at least one of the multiple fire risk zones using ASD 150 (for example, by drawing air into manifold 136). GT system 100 is operational during process P1. In processes P2-P3, system 104, for example, controller 170, generates a first (high temperature) alarm in response to a first temperature sensor 142 in manifold 136 detecting that the temperature of the gas flow 140 exceeds a first temperature threshold. That is, if the temperature of the gas flow 140 exceeds the first temperature threshold, i.e., Yes in process P2, then in process P3, controller 170 generates a first alarm. If the temperature of the gas flow 140 does not exceed the first temperature threshold, i.e., if the result in process P2 is No, then there is no fire and the process proceeds to process P1. As described above, the first (high temperature) alarm may indicate one of the following user-defined commands: a) an excessive heat detection alarm that may require passive corrective action, such as additional monitoring; b) a pre-fire alarm that may require passive corrective action, such as verification by other mechanisms, such as visual inspection; and c) a fire alarm that requires more proactive corrective action, such as fire suppression or emission control, or shutdown of the GT system 100. The controller 170 is configured to interact possibly with the overall controller (not shown) of the GT system 100 to implement one of the described corrective actions.

[0063] Simultaneously with processes P1 to P3, in process P4, system 104 uses cooling system(s) 164 to cool the gas flow 140 downstream of the first temperature sensor 142 and upstream of ASD(s) 150.

[0064] Processes P5-P6 describe the operation of a safety system 180, one of which is provided. In processes P5-P6, system 104, for example, controller 170, generates a third (ASD safety) alarm in response to a second temperature sensor 184 in manifold 136 detecting that the temperature of the gas flow 140 exceeds a second temperature threshold. That is, if the temperature of the gas flow 140 exceeds the second temperature threshold, i.e., Yes in process P5, in process P6, controller 170 generates a third alarm. If the temperature of the gas flow 140 does not exceed the second temperature threshold, i.e., No in process P5, the gas flow 140 is cool enough for the ASD 150, and processing proceeds to process P7. In addition, in process P6 (i.e., the ASD safety step), controller 170 can close valve 182 in manifold 136 upstream of cooling system 164, shutting off the ASD 150 and ceasing the generation of gas flow 140 and smoke detection. As described above, the second temperature threshold can be any user-defined temperature at which protection of the ASD150 is considered to be guaranteed. As described above, the third (ASD safety) alarm can include a user-defined format such as a visual or audible alarm, which can signal passive corrective actions such as manual monitoring or checking of the cooling system 164. In this way, the ASD150 can be protected from excessive temperatures.

[0065] If the temperature of the gas flow 140 does not exceed the second temperature threshold, i.e., if the answer is No in process P5, then in processes P7-P8, the controller 170 can generate a second (smoke) alarm in response to the ASD 150 detecting smoke in the gas flow 140. More specifically, in process P7, the ASD 150 determines whether smoke is present in the gas flow 140, for example, whether the smoke particle concentration exceeds a threshold. If smoke is detected (if the answer is Yes in process P7), then in process P8 (smoke alarm processing), the control unit 180 generates a second (smoke) alarm. As described above, the second (smoke) alarm may indicate one of the following user-defined commands: a) a smoke detection alarm which may require passive corrective actions such as additional monitoring and / or more definitive corrective actions such as fire suppression or emission control, or shutdown of the GT system 100; b) a pre-fire alarm which may require passive corrective actions such as verification by other mechanisms such as visual inspection; and c) a fire alarm which may require more definitive corrective actions such as fire suppression or emission control, or shutdown of the GT system 100. The controller 170 is configured to interact possibly with the overall controller of the GT system 100 (not shown) to implement any of the described corrective actions. If no smoke is detected, i.e., if the result in process P7 is No, there is no fire and processing proceeds to process P1.

[0066] Embodiments of the present disclosure offer various technical and commercial advantages, examples of which are discussed herein. System 104 provides early fire detection in GT system 100 and / or gas turbine housing 102 by providing a mechanism that enables the use of ASD(s). The system also uses high-temperature detection in addition to smoke detection for early warning of fire. A safety system may also be used to protect sensitive ASDs. Embodiments of the present disclosure can be retrofitted to existing GT systems or used with new installations.

[0067] The terms used herein are intended solely to describe specific embodiments and are not intended to limit the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form unless the context explicitly indicates otherwise. The terms “comprises” and / or “comprising,” when used herein, specify the presence of a described feature, integer, step, action, element, and / or component, but do not exclude the presence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups thereof. “Optional” or “optionally” means that the event or situation described thereafter may or may not occur, and that the description includes both the cases in which the event occurs and the cases in which it does not.

[0068] The approximation language used herein, as used herein, may be applied to modify any quantitative expression that is acceptablely variable without altering the underlying function of the expression. Therefore, values ​​modified by one or more terms such as “about,” “approximately,” and “substantially” should not be limited to the specified exact value. In at least some examples, the approximation language may correspond to the precision of the instrument used to measure the value. Herein, and throughout herein and the claims, limitations on range may be combined and / or interchangeable, and such range includes all subranges identified and contained therein, unless the context or language indicates otherwise. “About” applied to a particular value of a range may indicate + / - 10% of the stated value(s), unless it applies to both values ​​and is particularly dependent on the precision of the instrument used to measure the value(s).

[0069] All means or step-plus-function elements in the following claims are intended to include any structures, materials, or actions for performing a function in combination with other claimed elements specifically claimed. The descriptions in this disclosure are presented for illustrative and explanatory purposes, but are not intended to be exhaustive or to limit the disclosure to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of this disclosure. The embodiments have been selected and described to best illustrate the principles and practical applications of this disclosure and to enable others skilled in the art to understand this disclosure in terms of various embodiments with various modifications suitable for the particular use intended. [Explanation of Symbols]

[0070] 100 Gas Turbine Systems, GT Systems 102 Gas turbine enclosure 104 Fire Detection System 106 Compressor 108 Combustor, Combustion Section 110 Turbine, Turbine Section 112 Combustor can, combustor 114 Fuel supply system 116, 116X, 116Y fuel modules 130 Pipe intake port 132 pipes 136, 136A~G Manifold 140, 140A~G Gas Flow 142, 142A~G Upstream temperature sensor, first temperature sensor 150, 150A~G ASD, Suction-type smoke detector 154 Sensing Chamber 156 Nephelometer 158 Fans, Suction Devices 160 filters 164 Cooling System 166A~G Heat exchanger 170 Controllers 180 Safety systems, control units 182, 182A~G valves 184, 184A~G Downstream temperature sensor, second temperature sensor 232 pipes

Claims

1. A fire detection system (104) for a gas turbine system (100) including multiple fire risk zones, wherein the fire detection system (104) comprises: A pipe intake port (130) adjacent to each of the multiple fire risk zones within the housing (102) surrounding the gas turbine system (100), A manifold (136) that is in fluid communication with at least one of the pipe intake ports (130), A first temperature sensor (142) positioned within the manifold (136), A cooling system (164) located downstream of the first temperature sensor (142) in the manifold (136), wherein the cooling system (164) is configured to lower the temperature of the gas flow (140) in the manifold (136), A suction-type smoke detector (150) located downstream of the cooling system (164) within the manifold (136), wherein the suction-type smoke detector (150) is configured to draw in the gas flow (140) through the manifold (136) and detect smoke in the gas flow (140), A controller (170) that communicates with the first temperature sensor (142) and the suction-type smoke detector (150), wherein the controller (170) is configured to perform one of the following: a) generate a first alarm in response to the first temperature sensor (142) detecting a temperature in the gas flow (140) that exceeds a first temperature threshold, and b) generate a second alarm in response to the suction-type smoke detector (150) detecting smoke in the gas flow (140), A fire detection system (104) is provided.

2. A valve (182) in the manifold (136) upstream of the cooling system (164), A second temperature sensor (184) in the manifold (136) downstream of the cooling system (164) and upstream of the suction-type smoke detector (150), It also includes a safety system that includes, The controller (170) is further configured to generate a third alarm in response to the second temperature sensor (184) detecting that the temperature of the gas flow (140) exceeds a second temperature threshold. The fire detection system (104) according to claim 1.

3. The fire detection system (104) according to claim 2, wherein the controller (170) is further configured to close the valve (182) and shut off the suction-type smoke detector (150) in response to the second temperature sensor (184) detecting the temperature of the gas flow (140) exceeding the second temperature threshold.

4. The fire detection system (104) according to claim 1, wherein the first alarm includes one of an overheat detection alarm, a pre-fire alarm, and a fire alarm.

5. The fire detection system (104) according to claim 1, wherein the second alarm includes one of a smoke detection alarm, a pre-fire alarm, and a fire alarm.

6. The fire detection system (104) according to claim 1, further comprising a filter (160) upstream of the suction-type smoke detector (150).

7. The fire detection system (104) according to claim 1, wherein the plurality of fire risk zones include areas adjacent to at least some of the plurality of combustor canisters of the gas turbine system (100).

8. The fire detection system (104) according to claim 7, wherein the plurality of fire risk zones further include areas adjacent to at least one fuel module (116) of the gas turbine system (100).

9. The fire detection system (104) according to claim 1, wherein the manifold (136) extends to the outside of the housing (102), and the first temperature sensor (142), the cooling system (164), the suction-type smoke detector (150), and the controller (170) are located outside the housing (102).

10. The manifold (136) comprises a plurality of manifolds (136), each manifold (136) having fluid communication with at least one intake port, and each includes a first temperature sensor (142), a cooling system (164), and a suction-type smoke detector (150). The controller (170) communicates with each of the first temperature sensors (142) and each of the suction-type smoke detectors (150), and the controller (170) is configured to: a) generate a first alarm in response to any of the first temperature sensors (142) detecting a temperature in the gas flow (140) in each of the manifolds (136) that exceeds a first temperature threshold; and b) generate a second alarm in response to any of the suction-type smoke detectors (150) detecting smoke in the gas flow (140) in each of the manifolds (136). The fire detection system (104) according to claim 1.

11. A fire detection system (104) for a gas turbine system (100) including multiple fire risk zones, wherein the fire detection system (104) comprises: A pipe intake port (130) adjacent to each of the multiple fire risk zones within the housing (102) surrounding the gas turbine system (100), At least one manifold (136) is in fluid communication with at least one of the pipe intake ports (130), A first temperature sensor (142) is positioned within each manifold (136), A cooling system (164) located downstream of the first temperature sensor (142) in each manifold (136), wherein the cooling system (164) is configured to reduce the temperature of the gas flow (140) in each manifold (136), and The valves (182) in each manifold (136) upstream of each cooling system (164), A suction-type smoke detector (150) located downstream of the cooling system (164) in each manifold (136), wherein the suction-type smoke detector (150) is configured to draw in each gas flow (140) through each manifold (136) and detect smoke in each gas flow (140), A controller (170) that communicates with each first temperature sensor (142) and the suction-type smoke detector (150), wherein the controller (170) is configured to perform one of the following: a) generate a first alarm in response to any first temperature sensor (142) detecting a temperature in the gas flow (140) that exceeds a first temperature threshold, and b) generate a second alarm in response to any suction-type smoke detector (150) detecting smoke in each of the gas flow (140), Equipped with, The controller (170) is further configured to close the respective valves (182) and shut off the suction-type smoke detector (150) in response to the second temperature sensor (184) detecting that the temperature of the gas flow (140) in each of the manifolds (136) exceeds the second temperature threshold. Fire detection system (104).

12. The safety system further includes a second temperature sensor (184) in each manifold (136) downstream of each cooling system (164) and upstream of the suction-type smoke detector (150), The fire detection system (104) according to claim 11, wherein the controller (170) is further configured to generate a third alarm in response to each of the second temperature sensors (184) detecting a temperature of the gas flow (140) that exceeds a second temperature threshold.

13. In each of the manifolds (136), the valve (182) is located downstream of the first temperature sensor (142), the fire detection system (104) according to claim 11.

14. The fire detection system (104) according to claim 11, wherein the first alarm includes one of an excess heat detection alarm, a pre-fire alarm, and a fire alarm, and the second alarm includes one of a smoke detection alarm, a pre-fire alarm, and a fire alarm.

15. The fire detection system (104) according to claim 11, wherein the second alarm includes one of a smoke detection alarm, a pre-fire alarm, and a fire alarm.

16. The fire detection system (104) according to claim 11, further comprising a filter (160) upstream of the suction-type smoke detector (150).

17. The fire detection system (104) according to claim 11, wherein the plurality of fire risk zones include areas adjacent to at least some of the plurality of combustor cans of the gas turbine system (100), areas adjacent to at least one fuel module (116) of the gas turbine system (100), or both.

18. A method for detecting a fire in a gas turbine system (100) that includes multiple fire risk zones, wherein the method is: Using a suction-type smoke detector (150), a gas flow (140) is generated into the manifold (136) from at least one of the multiple fire risk zones, In response to the first temperature sensor (142) in the manifold (136) detecting that the temperature of the gas flow (140) exceeds a first temperature threshold, a first alarm is generated. The cooling system (164) is used to cool the gas flow (140) downstream of the first temperature sensor (142) and upstream of the suction-type smoke detector (150), In response to the suction-type smoke detector (150) detecting smoke in the gas flow (140), a second alarm is generated. Methods that include...

19. The method according to claim 18, further comprising generating a third alarm in response to a second temperature sensor (184) located downstream of the cooling system (164) and upstream of the suction-type smoke detector (150) detecting that the temperature of the gas flow (140) exceeds a second temperature threshold.

20. The method according to claim 19, further comprising, in response to the second temperature sensor (184) detecting the temperature of the gas flow (140) exceeding the second temperature threshold, closing a valve (182) in the manifold (136) upstream of the cooling system (164) and shutting off the suction smoke detector (150) to stop the generation of the gas flow (140) and the detection of the smoke.

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