WO2023092877A1 - Fume hood and fire-extinguishing method - Google Patents

Abstract

A fume hood, comprising a hood body (10) having an inner cavity, wherein the inner cavity constitutes a working cavity (11); a window (20) arranged on a front wall (101) of the hood body, wherein the window can move upwards or downwards in a height direction of the hood body; an exhaust system used for making air entering the working cavity be exhausted from the working cavity; a fire-extinguishing sensor arranged on a cavity wall of the working cavity; a fire-extinguishing device (40) used for storing a fire-extinguishing agent and arranged outside the working cavity; and a nozzle (50) arranged on the cavity wall of the working cavity and connected to the fire-extinguishing device. When the fire-extinguishing sensor detects that there is a fire source in the working cavity, the nozzle can inject the fire-extinguishing agent into the working cavity, the window moves downwards in the height direction of the hood body and closes, and the exhaust system is in a working state, such that the working cavity is in a negative pressure state, in order to implement fire extinguishing under a negative pressure. Further provided is a fire-extinguishing method.

Description

A kind of fume cupboard and fire extinguishing method technical field

The invention relates to the technical field of fume hoods, in particular to a fume hood and a fire extinguishing method.

Background technique

Ventilation equipment can generally be described as a device that removes exhaust gas, harmful gases, and particulate matter from a working space to the outside of the working space (usually outdoors). This type of equipment is widely used in industry and life, such as , factories that produce toxic and harmful or particulate gases in industrial production, biological and chemical laboratories of research and development institutions, kitchens that produce oily fumes during cooking, etc., all need ventilation equipment to isolate toxic gases and particulates in a certain working space from users , to prevent users from inhaling toxic and harmful gases and particles, and to discharge toxic and harmful gases and particles outdoors.

The fume hood is an important device for controlling pollutants in the laboratory. Its function is to control the pollutants emitted in the cabinet, and make it smoothly discharged to the outside, and will not escape into the room through the operation port of the fume cabinet, endangering the health and safety of the experimenters. In some cases, during the use of the fume hood, the cabinet will catch fire and generate a fire source, which will affect the safety of experimenters and equipment.

Therefore, it is necessary to extinguish the fire in time after the fume cupboard catches fire.

Contents of the invention

The purpose of the invention is to solve the technical problem that the fume cupboard catches fire. The invention provides a fume hood and a fire extinguishing method, which can realize "fire extinguishing under negative pressure" after the fume hood catches fire, and has little influence on the laboratory environment and experiments in the cabinet.

In order to solve the above-mentioned technical problems, the embodiment of the present invention discloses a fume cabinet, comprising: a cabinet body with an inner cavity, and the inner cavity constitutes a working cavity; a window is arranged on the front wall of the cabinet body, and the The viewing window can move up or down along the height direction of the cabinet; the exhaust system is used to discharge the air entering the working chamber from the working chamber; the fire sensor is arranged on the wall of the working chamber above; the fire extinguishing device is used to store the fire extinguishing agent and is arranged outside the working chamber; the nozzle is arranged on the wall of the working chamber, and the nozzle is connected to the fire extinguishing device; When the fire extinguishing sensor detects that there is a fire source in the working chamber, the fire extinguishing agent is sprayed into the working chamber, and the window is moved down along the height direction of the cabinet to close, and the exhaust system is in an open state. so that the working chamber is in a negative pressure state.

By adopting the above-mentioned technical scheme, the purpose of "fire extinguishing under negative pressure, effective fire extinguishing inside the cabinet, and safety outside the cabinet" can be achieved.

According to another specific embodiment of the present invention, the fire extinguishing agent is perfluorohexanone.

According to another specific embodiment of the present invention, it further includes: an air supply system, the air supply system is used to supply air to the working chamber, and when the fire extinguishing sensor detects that there is a fire source in the working chamber, the Make-up air system is off.

According to another specific embodiment of the present invention, the nozzle is arranged on the top cavity wall of the working cavity.

According to another specific embodiment of the present invention, the inner width of the fume cupboard is W, the inner depth of the fume cupboard is D, and the inner height of the fume cupboard is H;

Along the width direction of the fume hood, the width of the nozzle from the center line of the fume hood is W1, where 0mm≤W1≤0.32W;

Along the depth direction of the fume hood, the depth of the nozzle from the rear chamber wall of the fume hood is D1, where 0.3D≤D1≤0.5D;

Along the height direction of the fume hood, the height of the nozzle from the top chamber wall of the fume hood is H1, wherein 0mm<H1≤0.2H.

According to another specific embodiment of the present invention, wherein, 0mm<W≤1200mm, the number of the nozzle is one, W1=0mm; or, 1200mm<W≤1800mm, the number of the nozzle is two, each The width of the nozzle from the center line of the fume hood is W1, wherein, 0.17W≤W1≤0.25W; or, 1800mm<W≤2400mm, the number of the nozzles is three, one of which is located in the At the center line of the fume hood, the width of each of the remaining nozzles from the center line of the fume hood is W1, wherein, 0.25W≤W1≤0.32W.

According to another specific embodiment of the present invention, Q _min ≤ Q _row ≤ N*V, wherein, Q _row represents the fire extinguishing exhaust air volume of the exhaust system when the nozzle sprays fire extinguishing agent, and Q _min represents the exhaust air volume of the exhaust system. The minimum exhaust air volume of the wind system when the minimum number of air changes is guaranteed, N represents the number of air changes of the fume hood, V represents the volume of the working chamber of the fume hood, and the minimum number of air changes of the fume hood 150 times/hour. In some possible embodiments, N=200.

According to another specific embodiment of the present invention, the capacity of the fire extinguishing agent stored in the fire extinguishing device is G, G=(V/S)×C1×K; wherein, V represents the volume of the working chamber of the fume cabinet, S represents the specific volume of the fire extinguishing agent, C1 represents the fire extinguishing design concentration or inert design concentration, and K represents the pressure correction coefficient of the room where the fume hood is located.

According to another specific embodiment of the present invention, the pressure of the room is 0Pa, K=1; the pressure of the room is -2Pa, K=1.03; the pressure of the room is -5Pa, K=1.063; The pressure of the room is -8Pa, K=1.08.

According to another specific embodiment of the present invention, the fire extinguishing sensor is arranged on the top cavity wall of the working cavity and facing the bottom cavity wall of the working cavity.

According to another specific embodiment of the present invention, the fire extinguishing sensor includes any one or more of the following: a photoelectric smoke detector, a flame detector, and a temperature detector.

According to another specific embodiment of the present invention, the fume cabinet includes a controller, and the controller is connected with the window, the supplementary air system, the exhaust system, the fire extinguishing sensor, the nozzle, the Connect the fire extinguishing device described above.

The application also provides a method for extinguishing a fume cupboard, comprising:

A fire source is detected in the working chamber of the fume hood;

Control the window of the fume hood to move down and close along the height direction of the cabinet of the fume hood;

Control the exhaust system of the fume cupboard to be in an open state, so that the working chamber of the fume cupboard is in a negative pressure state;

The nozzles in the working chamber of the fume hood are controlled to spray the fire extinguishing agent to the working chamber of the fume hood.

According to another specific embodiment of the present invention, the fire extinguishing agent is perfluorohexanone.

According to another specific embodiment of the present invention, the fire extinguishing method further includes: controlling the make-up air system of the fume cupboard to be in a closed state, so that the working chamber of the fume cupboard is in a negative pressure state.

According to another specific embodiment of the present invention, a fire extinguishing sensor detects that there is a fire source in the working chamber of the fume hood, and controls the sound and light alarm to send out an alarm signal.

According to another specific embodiment of the present invention, at least two fire extinguishing sensors detect that there is a fire source in the working chamber of the fume cupboard, and control the nozzles to inject fire extinguishing agent into the working chamber of the fume cupboard.

According to another specific embodiment of the present invention, the time for controlling the make-up air system of the fume hood to be closed is 60 seconds, and the time for controlling the exhaust system of the fume hood to be open is 60 seconds.

According to another specific embodiment of the present invention, the nozzle is controlled to spray out the fire extinguishing agent in the fire extinguishing device within 10 seconds.

Description of drawings

Fig. 1 shows the perspective view one of the fume cupboard of the embodiment of the present invention;

Fig. 2 shows the front view one of the fume hood of the embodiment of the present invention;

Fig. 3 shows the side view one of the fume hood of the embodiment of the present invention;

Fig. 4 shows the perspective view of the fire extinguishing sensor in the fume cupboard of the embodiment of the present invention;

Fig. 5 shows the perspective view two of the fume cupboard of the embodiment of the present invention;

Fig. 6 shows the top view one of the fume hood of the embodiment of the present invention;

Fig. 7 shows the front view two of the fume hood of the embodiment of the present invention;

Fig. 8 shows the side view two of the fume hood of the embodiment of the present invention;

Fig. 9 shows the second top view of the fume hood according to the embodiment of the present invention;

Fig. 10 shows the top view three of the fume hood of the embodiment of the present invention;

Fig. 11 shows the top view four of the fume hood of the embodiment of the present invention;

Fig. 12 shows a three-dimensional view of the fume hood according to the embodiment of the present invention;

Fig. 13 shows the top view five of the fume hood of the embodiment of the present invention;

Fig. 14 shows the front view three of the fume hood of the embodiment of the present invention;

Fig. 15 shows the side view three of the fume hood of the embodiment of the present invention;

Fig. 16 shows the concentration graph of measuring point P1 outside the fume hood of the embodiment of the present invention;

Fig. 17 shows the concentration curve diagram of the fume hood external measuring point P2 of the embodiment of the present invention;

Fig. 18 shows the concentration curve diagram of the fume hood external measuring point P3 of the embodiment of the present invention;

Fig. 19 shows the concentration curve diagram of measuring point A1 inside the fume hood of the embodiment of the present invention;

Fig. 20 shows the concentration curve diagram of measuring point A2 inside the fume hood of the embodiment of the present invention;

Fig. 21 shows the concentration curve diagram of measuring point A3 inside the fume hood of the embodiment of the present invention;

Fig. 22 shows the concentration curve diagram of measuring point A4 inside the fume hood of the embodiment of the present invention;

Fig. 23 shows the concentration graph of measuring point A5 inside the fume hood of the embodiment of the present invention;

Fig. 24 shows the concentration curve diagram of measuring point A6 inside the fume hood of the embodiment of the present invention;

Fig. 25 shows the concentration graph of measuring point A7 inside the fume hood of the embodiment of the present invention;

Fig. 26 shows the concentration graph of measuring point A8 inside the fume hood of the embodiment of the present invention;

Fig. 27 shows the concentration graph of measuring point A9 inside the fume hood of the embodiment of the present invention;

Fig. 28 shows the concentration curve diagram of measuring point B1 inside the fume hood according to the embodiment of the present invention;

Fig. 29 shows the concentration curve diagram of measuring point B2 inside the fume hood of the embodiment of the present invention;

Fig. 30 shows the concentration graph of measuring point B3 inside the fume hood of the embodiment of the present invention;

Fig. 31 shows the concentration graph of measuring point B4 inside the fume hood of the embodiment of the present invention;

Fig. 32 shows the concentration graph of measuring point B5 inside the fume hood of the embodiment of the present invention;

Fig. 33 shows the concentration graph of measuring point B6 inside the fume hood of the embodiment of the present invention;

Fig. 34 shows the concentration graph of measuring point B7 inside the fume hood of the embodiment of the present invention;

Fig. 35 shows the concentration graph of measuring point B8 inside the fume hood of the embodiment of the present invention;

Fig. 36 shows the concentration graph of measuring point B9 inside the fume hood of the embodiment of the present invention;

Fig. 37 shows the isosurface of the first second when the concentration of fire extinguishing agent in the fume hood of the embodiment of the present invention is 5.9%;

Fig. 38 shows the isosurface of the second second when the concentration of fire extinguishing agent in the fume hood of the embodiment of the present invention is 5.9%;

Fig. 39 shows the isosurface of the 3rd second when the concentration of fire extinguishing agent in the fume hood of the embodiment of the present invention is 5.9%;

Figure 40 shows the concentration of the fire extinguishing agent in the fume hood of the embodiment of the present invention when it is 5.9%, the isosurface of the 4th second;

Figure 41 shows the isosurface of the 5th second when the concentration of fire extinguishing agent in the fume hood of the embodiment of the present invention is 5.9%;

Fig. 42 shows the concentration of fire extinguishing agent in the fume hood of the embodiment of the present invention when 5.9%, the isosurface of the 6th second;

Fig. 43 shows the isosurface of the 7th second when the concentration of the fire extinguishing agent in the fume hood of the embodiment of the present invention is 5.9%;

Figure 44 shows the concentration of the fire extinguishing agent in the fume hood of the embodiment of the present invention when the concentration is 5.9%, the isosurface of the 8th second;

Fig. 45 shows the isosurface of the 9th second when the concentration of the fire extinguishing agent in the fume hood of the embodiment of the present invention is 5.9%;

Fig. 46 shows the isosurface at the 10th second when the concentration of the fire extinguishing agent in the fume hood is 5.9% according to the embodiment of the present invention.

Detailed ways

The implementation of the present invention will be illustrated by specific specific examples below, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be presented in conjunction with a preferred embodiment, it does not mean that the features of the invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiments is to cover other options or modifications that may be extended based on the claims of the present invention. The following description contains numerous specific details in order to provide a thorough understanding of the present invention. The invention may also be practiced without these details. Also, some specific details will be omitted from the description in order to avoid obscuring or obscuring the gist of the present invention. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

It should be noted that in this specification, similar numerals and letters denote similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be identified in subsequent drawings. for further definition and explanation.

In the description of this embodiment, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "bottom" etc. is based on the orientation or positional relationship shown in the drawings, or is The conventionally placed orientation or positional relationship of the inventive product during use is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention.

The terms "first", "second", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In the description of this embodiment, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "connecting" and "connecting" should be understood in a broad sense, for example, it can be a fixed connection or a A detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediary, and it may be an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this embodiment in specific situations.

In order to make the purpose, technical solution and advantages of the present invention clearer, the following will further describe the implementation of the present invention in detail in conjunction with the accompanying drawings.

In some possible implementation manners, a fire detection pipe is arranged in the cabinet of the fume cabinet. When a fire breaks out in the cabinet of the fume cupboard, the 170-degree flame burns through the fire detection pipe, and the fire extinguishing agent is ejected from the breach, thus realizing fire extinguishing. Or, in some possible implementations, the flame burns through the fire detection tube, the pressure in the fire detection tube drops, and the pressure drop signal triggers the solenoid valve at the mouth of the fire extinguishing device to open, and the fire extinguishing agent is sprayed from the nozzle of the metal pipe to realize fire extinguishing. But this fire extinguishing method can't be extinguished in time for early fire. After the fire extinguishing agent in the fire extinguishing device is sprayed, the pressure inside the cabinet of the fume cabinet will rise, and the toxic and harmful gas in the cabinet will leak into the laboratory space.

For this reason, the present application provides another fire extinguishing method: fire extinguishing under negative pressure, which has little impact on the laboratory environment and experiments in the cabinet.

Exemplarily, referring to FIG. 1 to FIG. 14 , the present application provides a fume cabinet 1 , including a cabinet body 10 . The cabinet body 10 has a front wall 101 , a rear cavity wall 103 , a left wall 105 , a right wall 106 , a top cavity wall 104 and a bottom cavity wall 102 . Wherein, the front wall 101 and the rear cavity wall 103 are relatively arranged along the depth direction of the fume cupboard 1 (shown in the Z direction in FIG. Shown in the X direction) are relatively arranged, and the top cavity wall 104 and the bottom cavity wall 102 are relatively arranged along the height direction of the fume hood 1 (shown in the Y direction in FIGS. 1 to 3 , FIG. 8 , and FIG. 12 ). The above-mentioned cavity wall encloses the inner cavity of the cabinet body 10 , and the inner cavity constitutes the working cavity 11 of the fume cupboard 1 .

Wherein, when the fume cupboard 1 is placed in an indoor environment, the wall body of the cabinet body 10 that the user works on is the front wall 101 . A window 20 is provided on the front wall 101 of the cabinet body 10, and the window 20 can be moved upwards along the height direction of the cabinet body 10 (shown in the Y direction in FIGS. An open front opening, the front opening is used as an operation port; or, the viewing window 20 moves downward along the height direction of the cabinet body 10 .

The fume cupboard 1 of the present application also includes a make-up air system and an air exhaust system. The supplementary air system is used to supply air to the working chamber 11 , and the exhaust system is used to exhaust the air entering the working chamber 11 from the working chamber 11 . Exemplarily, the supplementary air system includes a supplementary air valve and a supplementary air port provided on the fume hood 1 . The exhaust system includes an exhaust damper and an exhaust port 12 arranged on the fume cupboard 1 . Exemplarily, the air outlet 12 on the fume hood 1 is arranged on the top of the fume hood 1 . In some possible implementations, the fume hood 1 does not include a make-up air system.

A fire extinguishing sensor and a nozzle 50 are arranged on the cavity wall of the working cavity 11 of the cabinet body 10 . Exemplarily, the above-mentioned fire extinguishing sensor and nozzle 50 are arranged on the top chamber wall 104 of the working chamber 11 . A fire extinguishing device 40 is provided outside the working chamber 11 of the cabinet body 10 . Exemplarily, the fire extinguishing device 40 is disposed on the top of the cabinet body 10 . The fire extinguishing device 40 is used to store a fire extinguishing agent and is connected to the nozzle 50 . Exemplarily, the fire extinguishing device 40 is connected to the nozzle 50 through a fire extinguishing agent pipeline 43 to provide the fire extinguishing agent to the nozzle 50 . The number of nozzles 50 is not limited, and can be set accordingly according to the requirements of fire extinguishing, for example, the number of nozzles 50 is one, two or three.

Exemplarily, the fire extinguishing sensor includes any one or more of the following: photoelectric smoke detector 30 , flame detector 32 (infrared flame detector and ultraviolet flame detector), temperature detector 31 . As shown in FIGS. 2 to 4 , the fire extinguishing sensor in this application includes: a photoelectric smoke detector 30 , a flame detector 32 and a temperature detector 31 . The photoelectric smoke detector 30 , the flame detector 32 and the temperature detector 31 are arranged on the fire extinguishing mounting plate, and are connected with the cavity wall of the working chamber 11 (for example, the top cavity wall 104 ) through the fire extinguishing mounting plate. There is no limitation on the connection method between the fire extinguishing installation plate and the cavity wall of the working cavity 11 . For example, in the present application, a screw hole 331 is provided on the fire extinguishing mounting plate, and the screw hole 331 of the fire extinguishing mounting plate is fixedly connected to the cavity wall of the working chamber 11 by screws (not shown).

In the present application, the above-mentioned nozzle 50 can spray fire extinguishing agent to the working chamber 11 when the fire sensor detects that there is a fire source in the working chamber 11, and the window 20 moves downward along the height direction of the cabinet body 10 to close, and the supplementary air system is in the state of In the closed state, the exhaust system is in the open state, so that the working chamber 11 is in a negative pressure state. That is, when the fire extinguishing sensor detects that there is a fire source in the working chamber 11, it means that a fire is caught in the working chamber 11 of the fume hood 1, and the window 20 can move downwards and close (cutting off oxygen replenishment, preventing pollutants, and fire extinguishing agent from overflowing), And the supplementary air system is in closed state (cutting off the oxygen supply), the exhaust system is in open state, and the exhaust air volume is adjusted to the fire extinguishing exhaust air volume value, so that the working chamber 11 of the fume cupboard 1 is in a negative pressure state.

When the fume cupboard 1 is in a negative pressure state, the fire extinguishing agent in the fire extinguishing device 40 is sprayed to the fire source in the working chamber 11 through the nozzle 50 to realize fire extinguishing under negative pressure, which has little influence on the laboratory environment and experiments in the cabinet . After the fire extinguishing agent in the fire extinguishing device 40 is sprayed, the pressure in the cabinet body 10 of the fume cabinet 1 increases, reducing the possibility of toxic and harmful gases in the cabinet leaking into the laboratory space. To achieve the purpose of "fire extinguishing under negative pressure, effective fire extinguishing inside the cabinet, and safety outside the cabinet".

In some possible implementations, when the fume cupboard does not include a make-up air system, when the fire sensor detects that there is a fire source in the working chamber 11, it means that there is a fire in the working chamber 11 of the fume cupboard 1, and the window 20 will turn to the Move down and close (cut off oxygen supplement, prevent pollutant, fire extinguishing agent from overflowing), exhaust system is in open state, makes the working chamber 11 of fume cupboard 1 be in negative pressure state.

Exemplarily, when any one of the above-mentioned photoelectric smoke detectors 30, flame detectors 32, and temperature detectors 31 detects that there is a fire source in the working chamber 11, the nozzle 50 can spray fire to the working chamber 11 agent. The timeliness of fire extinguishing of the fume cupboard 1 by the fire extinguishing device 40 is improved.

In some possible implementations, when one of the fire extinguishing sensors detects that there is a fire source in the working chamber 11, the fume cupboard 1 sends an alarm signal, and the nozzle 50 in the fume cupboard 1 will not spray to the working chamber of the fume cupboard 1. Extinguishing agent. In some possible implementations, when at least two fire extinguishing sensors detect that there is a fire source in the working chamber 11 , the nozzle 50 in the fume cupboard 1 sprays fire extinguishing agent into the working chamber of the fume cupboard 1 .

In some possible implementations, the fire extinguishing agent stored in the fire extinguishing device 40 is perfluorohexanone.

Perfluorohexanone: BI1230, named dodecafluoro-2-methyl-pentanone. Perfluorohexanone has the following characteristics: (1) Its boiling point is higher than other gaseous fire extinguishing agents, and it is liquid at room temperature. transportation. (2) The heat of vaporization of perfluorohexanone is only 1/25 of that of water, and its vapor pressure is 12 times that of water, so it is easy to vaporize, even at low temperature (-25°C), it can be effectively vaporized and diffused to it Protected space, eliminate fire, protect the safety of personnel and equipment, and leave no trace. (3) Perfluorohexanone does not contain solid particles, grease, chlorine and bromine and other chemical components that destroy the ozone layer. It is non-conductive, volatile, leaves no traces, is non-corrosive, and does not damage electronic components and circuits. (4) Perfluorohexanone has been approved by the EPA of the US Environmental Protection Agency and complies with the registration requirements of SNAP (Significant New Alternatives Policy). Can be used in places with people, no harm to human body. Typical application places include: fire in computer rooms, data centers, military industry, equipment warehouses, aviation, ships, vehicles, libraries, oil and gas production, etc. (5) There is no obvious chemical reaction to common metal and rubber sealing materials, no damage to electronic components and circuits, and it is compatible with a wide range of structural materials.

Perfluorohexanone has a good fire extinguishing effect. Its mechanism is to extinguish fire through physical and chemical effects. It can be divided into three processes: first: cooling down and extinguishing fire. Vaporization, due to the large heat capacity of vaporization, has a strong heat absorption capacity, which makes the flame lose heat quickly and destroys the tetrahedron balance of the fire. Second: smothering fire, perfluorohexanone has a large specificity, and can isolate the oxygen in the air around the flame during the suspension and falling process. Third: chemical suppression of fire extinguishing, which can capture the free radicals of the combustion chain reaction and terminate the chain reaction of flame propagation. Typical design concentrations range from 4.5 to 5.9 volume percent.

In some possible implementations, referring to FIG. 2 , FIG. 3 , FIG. 8 , and FIG. 15 , as mentioned above, the nozzle 50 is disposed on the top chamber wall 104 of the working chamber 11 . That is, along the height direction of the fume cupboard 1 , the nozzle 50 is disposed facing the bottom cavity wall 102 of the working cavity 11 . After setting in this way, it is convenient to spray fire extinguishing agent to the fire source in the working chamber 11, so as to realize fire extinguishing in time. Exemplarily, the nozzle 50 is installed directly above the potential fire equipment, and the nozzle 50 faces downward. In this way, the concentration of the fire extinguishing agent is high, and the fire extinguishing efficiency is higher.

In some possible implementation manners, the fire extinguishing sensor is installed directly above the potential fire equipment, and the fire extinguishing sensor faces downward. After this setting, the detection distance is short and the response speed is fast.

In some possible implementations, referring to Fig. 6 to Fig. 11, along the width direction of the fume hood 1 (shown in the X direction in Fig. 6, Fig. 7, Fig. 9 to Fig. 11), the inner width of the above-mentioned fume hood 1 is is W; along the depth direction of the fume cupboard 1 (shown in the Z direction in Fig. 8), the inner depth of the fume cupboard 1 is D; along the height direction of the fume cupboard 1 (shown in the Y direction in Fig. 8 to Fig. 11 ), the internal height of the fume hood 1 is H.

Wherein, along the width direction of the fume cupboard 1, the width of the nozzle 50 from the center line of the fume cupboard 1 is W1 (as shown in Fig. 6, Fig. 10, Fig. 11), wherein, 0mm≤W1≤0.32W. The centerline of the fume cupboard 1 is, for example, the symmetrical centerline along the width direction. The plane A shown in FIG. 6, FIG. 7, FIG. 10 and FIG. The centerline of is in the A plane. Along the depth direction of the fume hood 1, the depth of the nozzle 50 from the rear wall of the fume hood 1 (ie, the rear wall 103) is D1 (as shown in FIG. 8 ), where 0.3D≤D1≤0.5D ; Along the height direction of the fume hood 1, the height of the nozzle 50 from the top chamber wall 104 of the fume hood 1 is H1 (as shown in FIG. 8 ), where 0mm<H1≤0.2H.

In some possible implementations, the specific number of nozzles 50 and the specific value of the width W1 of the nozzles 50 from the centerline of the fume hood 1 can be set according to the width W of the fume hood 1 .

Exemplarily, referring to FIG. 9 , 0mm<W≤1200mm, the number of the nozzle 50 is one, and W1=0mm. That is, when the width W of the fume cupboard 1 is within the above range, one nozzle 50 is provided at the centerline of the fume cupboard 1 to realize effective fire extinguishing.

For example, referring to FIG. 10 , 1200mm<W≤1800mm, the number of nozzles 50 is two, and the width of each nozzle 50 from the centerline of the fume cupboard 1 is W1, wherein, 0.17W≤W1≤0.25W. That is, when the width W of the fume cupboard 1 is within the above range, two nozzles 50 are provided in the fume cupboard 1 , and the distances from the two nozzles 50 to the central line A are equal, so that effective fire extinguishing can be realized. Exemplarily, the width W of the fume hood 1 is 1466mm. The distance between the two nozzles 50 is 600mm.

Exemplarily, referring to FIG. 11 , 1800mm<W≤2400mm, the number of nozzles 50 is three, one of which is located at the centerline of the fume hood 1, and each of the other nozzles 50 is at a distance from the fume hood 1. The width of the center line is W1, where 0.25W≤W1≤0.32W. That is, when the width W of the fume cupboard 1 is within the above-mentioned range, three nozzles 50 are provided in the fume cupboard 1 to realize effective fire extinguishing. The three nozzles 50 are arranged in a row along the width direction of the fume hood 1 . The distance between two adjacent nozzles 50 is equal.

In some possible implementations, Q _min ≤ Q _row ≤ N*V, where Q _row represents the fire extinguishing exhaust air volume of the exhaust system when the nozzle 50 sprays the fire extinguishing agent, and Q _min represents that the exhaust system ensures the minimum air change The minimum exhaust air volume at times, N represents the number of air changes of the fume hood 1, V represents the volume of the working chamber 11 of the fume hood 1 (V=W*D*H), the minimum number of air changes of the fume hood 1 150 times/hour. Within the above range, it is beneficial to realize that the fume hood 1 is in a negative pressure state. In some possible implementations, Q _min =N*V=150*1.51=226.5m ³ /h, V: volume inside the cabinet=1.51m ³ . In some possible embodiments, N=200.

In some possible implementations, the capacity of the fire extinguishing agent stored in the fire extinguishing device 40 is G, G=(V/S)×C1×K; wherein, V represents the volume of the working chamber 11 of the fume hood 1, and S represents the fire extinguishing The specific volume of the agent, C1 represents the fire extinguishing design concentration or inert design concentration, K represents the pressure correction coefficient of the room where the fume hood 1 is located. The effective fire extinguishing of the fume hood 1 can be realized through the calculation formula of the above-mentioned capacity of the fire extinguishing agent.

Exemplarily, the pressure of the above room is 0Pa, K=1; the pressure of the room is -2Pa, K=1.03; the pressure of the room is -5Pa, K=1.063; the pressure of the room is -8Pa, K=1.08.

For example, the amount of fire extinguishing agent G _1.5 for the 1.5-meter fume hood 1 . V _1.5 : The internal volume is: length*width*height=1.47m*0.79m*1.3m=1.51m ³ . S: 0.0719m ³ /kg; C1: fire extinguishing range of 4.5%-5.9%, take the maximum value of 5.9%; the pressure of the room is -5Pa, K is 1.063. G _1.5 =(V/S)*C ₁ *K=(1.51/0.0719)*0.059*1.063=1.31kg, after adding 10% safety margin, G _1.5 =1.31*(1+10%)=1.44kg.

After spraying within 10s, calculate flow volume Q _1.5 =V/T, V=G _1.5 /ρ. In the formula: V represents the volume in gaseous state (m ³ ), T represents the injection time s, here it is sprayed within 10 s; ρ represents the density in gaseous state, here it is 0.0136g/cm ³ . Q _1.5 =(1.44/13.6)/10*3600=38.1 m ³ /h.

Therefore, the fire extinguishing dose required by the fume hood 1 for fire extinguishing can be met through the above formula for calculating the amount of fire extinguishing agent.

In some possible implementations, referring to FIG. 1 , the fume cupboard 1 of the present application includes a controller 60 connected to the window 20 , supplementary air system, exhaust system, fire extinguishing sensor, nozzle 50 , and fire extinguishing device 40 . Wherein, the controller 60 is connected to the fire sensor through a first cable 61 . The fire extinguishing device 40 includes a fire extinguishing control valve 41 , and the fire extinguishing control valve 41 is connected to the controller 60 through a second cable 42 . Thereby, when the fire extinguishing sensor detects that there is a fire source in the fume hood 1, the controller 60 controls the window 20 to move downward along the height direction of the fume hood 1, and controls the control valve 41 of the fire extinguishing device 40 so that the fire extinguishing device 40 moves toward the nozzle. 50 provides fire extinguishing agent.

In some possible implementations, the fume hood 1 of the present application further includes an audible and visual alarm connected to the controller 60 . When the fire extinguishing sensor detects that there is a fire source in the fume cupboard 1, the controller 60 controls the sound and light alarm to send out an alarm signal.

The application also provides a method for extinguishing a fume hood 1, comprising:

It is detected that there is a fire source in the working chamber 11 of the fume hood 1 , for example, the fire sensor in the above embodiment detects that there is a fire source in the working chamber 11 of the fume hood 1 .

Control the window 20 of the fume cupboard 1 to move downwards along the height direction of the cabinet body 10 of the fume cupboard 1 to close. Wind cabinet 1 height direction moves downwards, to cut off the supplement of oxygen, prevent pollutant, the overflow of fire extinguishing agent.

Control the supplementary air system of the fume cupboard 1 to be in the closed state (cut off the oxygen supply), and the exhaust system of the fume cupboard 1 is in the open state, so that the working chamber 11 of the fume cupboard 1 is in a negative pressure state. For example, the above-mentioned controller 60 controls the supplementary air system of the fume cupboard 1 to be in the closed state, and controls the exhaust system of the fume cupboard 1 to be in the open state, so that the working chamber 11 of the fume cupboard 1 is in a negative pressure state. In some possible implementations, the fume hood 1 does not include a make-up air system. Therefore, it is detected that there is a fire source in the working chamber 11 of the fume cupboard 1 , and the exhaust system of the fume cupboard is controlled to be closed, so that the working chamber of the fume cupboard is in a negative pressure state.

The nozzle 50 in the working chamber 11 of the fume hood 1 is controlled to inject the fire extinguishing agent into the working chamber 11 of the fume hood 1 . For example, the above-mentioned controller 60 controls the nozzle 50 to spray the fire extinguishing agent to the working chamber 11 of the fume hood 1 . The fire extinguishing agent sprayed by the nozzle 50 is, for example, perfluorohexanone.

In some possible implementations, the above-mentioned one fire extinguishing sensor detects that there is a fire source in the working chamber of the fume cupboard 1, and controls the sound and light alarm to send an alarm signal, and the nozzle 50 will not spray fire extinguishing agent into the working chamber 11 of the fume cupboard 1. .

In some possible implementations, when at least two fire extinguishing sensors detect that there is a fire source in the working chamber of the fume hood, the control nozzle 50 sprays fire extinguishing agent into the working chamber 11 of the fume hood 1 . It can prevent accidental spraying of fire extinguishing agent.

In some possible implementations, the time for controlling the make-up air system of the fume hood 1 to be closed is 60 seconds, and the time for controlling the exhaust system of the fume hood 1 to be in the open state is 60 seconds. Within this time parameter range, the fume cupboard 1 can be placed in a negative pressure state to realize fire extinguishing under negative pressure.

In some possible implementations, the nozzle 50 is controlled to spray out the fire extinguishing agent in the fire extinguishing device 40 within 10 seconds. That is, when there is a fire source in the working chamber 11 of the fume hood 1, the fire extinguishing device 40 will spray all the fire extinguishing agent within 10 seconds, so as to effectively extinguish the fire of the fume hood 1.

The fire extinguishing effect of the fume hood 1 of the present application in the above-mentioned embodiment will be described below with reference to FIGS. 12 to 46 . Two nozzles 50 are set in the working chamber 11 of the fume hood 1 as an example, and the fire extinguishing agent is sprayed out within 10 seconds as an example.

The establishment of physical model: build by 1.5 meters fume hood, window 20 is in closed state (still having opening 35mm, is used for indoor ventilation), as shown in Figure 15, the distance of window 20 apart from bottom cavity wall 102 along height direction is 35mm. The exhaust air volume Q _row of fume cupboard 1 is: 226.5cmh, the volume flow rate of fire extinguishing agent is 38.1cmh, and the volume flow rate of each nozzle 50 is 19.05cmh. Referring to FIG. 13 , one of the nozzles 50 is 433 mm away from the left wall 105 in the width direction, and the other nozzle 50 is 433 mm away from the right wall 106 in the width direction.

The basis for judging the internal fire extinguishing of the working chamber 11 of the fume hood 1 is: the inner side is divided into 2 layers, each layer has 9 measuring points, a total of 18 measuring points. With reference to Fig. 12, along the height direction of fume cupboard 1 (shown in Y direction in Fig. 12), two layers of measuring points (shown in B layer and C layer in Fig. 12) are provided, wherein, B layer is provided with 9 measuring points Points are B1 to B9, and there are 9 measuring points on the C floor, respectively A1 to A9. In the concentration curve of each measuring point within 10s, the curve has a concentration exceeding 5.9%, which means fire extinguishing.

Referring to Figure 14, the middle measuring points (B2, B5, B8, A2, A5, A8) of the B and C floors are located at the center line A of the fume hood 1, and the left measuring points of the B and C floors (B1, B4, B7, A1, A4, A7) are 83mm away from the left wall 105 along the width direction, and the right measuring points (B3, B6, B9, A3, A6, A9) of the B and C floors are 83mm away from the left side wall along the width direction. The distance of the walls 105 is 83mm.

Referring to Fig. 15, along the height direction of fume hood 1, the measuring point on layer B is 350mm away from the measuring point on layer C, and the measuring point on layer C is 50mm away from the bottom cavity wall 1024. Along the depth direction of the fume hood 1, the distance between the front measuring points (B1, B2, B3, A1, A2, A3) of the B and C floors and the front wall 101 is 150mm, and the rear measuring points of the B and C floors (B7, B8, B9, A7, A8, A9) are 103mm away from the rear wall 103, and the distance between the middle measuring points (B4, B5, B6, A4, A5, A6) of B and C floors is 103mm. The front measuring point is 224mm.

The basis for judging the external leakage pollution of the fume hood 1: refer to Figure 12 and Figure 15, along the depth direction of the fume hood 1, the outside is 75 mm outside the window 20, and three measuring points (P1, P2, P3) are set on the opening surface , Measure the concentration of the left (P1 measuring point), middle (P2 measuring point) and right (P3 measuring point) 3 points, and the required value should not exceed 10%.

Wherein, with reference to Fig. 14, along the width direction of the fume hood 1, the distance between the left point (P1 measuring point) and the left wall 1052 is 83 mm, the distance between the right point (P3 measuring point) and the left wall 1052 is 83 mm, and the middle point (P2 measuring point) is located at the center line A of the fume hood 1.

Through multiple simulations, the fire extinguishing effect of the above-mentioned fume hood 1 meets the requirements. For details, see the description of the following figure:

Figure 16 shows the concentration value of the P1 measuring point, Figure 17 shows the concentration value of the P2 measuring point, and Figure 18 shows the concentration value of the P3 measuring point, according to Figure 16 to Figure 18, the external three The concentration value of each measuring point shall not exceed 10%. Therefore, the external leakage pollution of the fume hood 1 meets the requirements.

What Figure 19 shows is the concentration value of the A1 measuring point, what Figure 20 shows is the concentration value of the A2 measuring point, what Figure 21 shows is the concentration value of the A3 measuring point, and what Figure 22 shows is the concentration of the A4 measuring point What Figure 23 shows is the concentration value of the A5 measuring point, what Figure 24 shows is the concentration value of the A6 measuring point, what Figure 25 shows is the concentration value of the A7 measuring point, and what Figure 26 shows is the concentration value of the A8 measuring point Figure 27 shows the concentration value of the A9 measuring point. According to Figure 19 to Figure 27, the fire extinguishing concentration values of the nine measuring points on the B layer exceed 5.9%. Therefore, effective fire extinguishing is realized in the fume hood 1 .

What Figure 28 shows is the concentration value of the B1 measuring point, what Figure 29 shows is the concentration value of the B2 measuring point, what Figure 30 shows is the concentration value of the B3 measuring point, and what Figure 31 shows is the concentration of the B4 measuring point What Figure 32 shows is the concentration value of the B5 measuring point, what Figure 33 shows is the concentration value of the B6 measuring point, what Figure 34 shows is the concentration value of the B7 measuring point, and what Figure 35 shows is the concentration value of the B8 measuring point Figure 36 shows the concentration value of the B9 measuring point. According to Figure 28 to Figure 36, the fire extinguishing concentration values of the nine measuring points on the C layer exceed 5.9%. Therefore, effective fire extinguishing is realized in the fume hood 1 .

Figures 37 to 46 respectively show the isosurface per second when the concentration of the fire extinguishing agent in the fume hood 1 is 5.9% from the first second to the tenth second. By establishing a CFD physical model, a transient analysis is performed on each measuring point in the fume hood 1, and each measuring point reaches a concentration of 5.9% within 10 seconds, and it is judged as fire extinguishing. By establishing a CFD physical model, a transient analysis is performed on each measuring point outside the fume hood 1. If the concentration of each measuring point is lower than 10% within 10s, it is judged to be safe.

In summary, it is obtained through CFD analysis that for the fume cupboard 1 of the present application, when the number of spray nozzles is 2 and the position of the nozzle 50 is the position of the above-mentioned embodiment, it can achieve fire extinguishing in the fume cupboard 1 cabinet, and the fume cupboard 1 The purpose of safety outside the cabinet.

Although the present invention has been illustrated and described with reference to some preferred embodiments of the present invention, those skilled in the art should understand that the above content is a further detailed description of the present invention in conjunction with specific embodiments, and cannot be deemed Embodiments of the present invention are limited only by these descriptions. Those skilled in the art may make various changes in form and details, including some simple deduction or substitution, without departing from the spirit and scope of the present invention.

Claims (20)

1. A kind of fume cupboard, it is characterized in that, comprises:

   The cabinet body has an inner cavity, and the inner cavity constitutes a working cavity;

   A viewing window is located on the front wall of the cabinet, and the viewing window can move upwards or downwards along the height direction of the cabinet;

   an exhaust system for exhausting the air entering the working chamber from the working chamber;

   The fire extinguishing sensor is arranged on the cavity wall of the working cavity;

   A fire extinguishing device, used for storing fire extinguishing agent, is arranged outside the working chamber;

   The nozzle is arranged on the cavity wall of the working chamber, and the nozzle is connected with the fire extinguishing device; wherein,

   When the fire extinguishing sensor detects that there is a fire source in the working chamber, the nozzle can spray fire extinguishing agent to the working chamber, and the window moves downward along the height direction of the cabinet to close. The wind system is in an open state, so that the working chamber is in a negative pressure state.
2. The fume hood according to claim 1, wherein the fire extinguishing agent is perfluorohexanone.
3. The fume cabinet according to claim 1 or 2, further comprising: an air supply system, the air supply system is used to supply air to the working chamber, and the fire extinguishing sensor detects When there is a fire source, the supplementary air system is in a closed state.
4. The fume hood according to any one of claims 1 to 3, wherein the nozzle is arranged on the top wall of the working chamber.
5. The fume cupboard as claimed in claim 4, wherein the interior width of the fume cupboard is W, the interior depth of the fume cupboard is D, and the interior height of the fume cupboard is H;

   Along the width direction of the fume hood, the width of the nozzle from the center line of the fume hood is W1, where 0mm≤W1≤0.32W;

   Along the depth direction of the fume hood, the depth of the nozzle from the rear chamber wall of the fume hood is D1, where 0.3D≤D1≤0.5D;

   Along the height direction of the fume hood, the height of the nozzle from the top chamber wall of the fume hood is H1, wherein 0mm<H1≤0.2H.
6. The fume hood as claimed in claim 5, wherein,

   0mm<W≤1200mm, the number of the nozzle is one, W1=0mm; or,

   1200mm<W≤1800mm, the number of the nozzles is two, and the width of each nozzle from the center line of the fume hood is W1, wherein, 0.17W≤W1≤0.25W; or,

   1800mm<W≤2400mm, the number of the nozzles is three, one of the nozzles is set at the centerline of the fume hood, and the width of each of the remaining nozzles from the centerline of the fume hood is W1 , where, 0.25W≤W1≤0.32W.
7. The fume cupboard according to any one of claims 1 to 6, characterized in that, Q _min ≤ Q _row ≤ N*V, wherein Q _row represents the fire extinguishing of the exhaust system when the nozzle sprays the fire extinguishing agent Exhaust air volume, Q _min represents the minimum exhaust air volume of the exhaust system when the minimum number of air changes is guaranteed, N represents the number of air changes of the fume cupboard, V represents the volume of the working chamber of the fume cupboard, The minimum air change rate of the fume hood is 150 times/hour.
8. The fume hood according to claim 7, wherein N=200.
9. The fume hood as claimed in any one of claims 1 to 8, wherein the capacity of the fire extinguishing agent stored in the fire extinguishing device is G, G=(V/S)×C1×K; wherein, V represents the The volume of the working chamber of the fume hood, S represents the specific volume of the fire extinguishing agent, C1 represents the fire extinguishing design concentration or inert design concentration, and K represents the pressure correction coefficient of the room where the fume hood is located.
10. The fume hood as claimed in claim 9, wherein the pressure of the room is 0Pa, K=1; the pressure of the room is-2Pa, K=1.03; the pressure of the room is-5Pa, K = 1.063; the pressure of the room is -8 Pa, K = 1.08.
11. The fume hood according to any one of claims 1 to 10, characterized in that the fire extinguishing sensor is arranged on the top wall of the working chamber and facing the bottom wall of the working chamber.
12. The fume hood according to any one of claims 1 to 11, wherein the fire extinguishing sensor includes any one or more of the following: photoelectric smoke detectors, flame detectors, and temperature detectors.
13. The fume cupboard according to any one of claims 1 to 12, characterized in that, the fume cupboard comprises a controller, and the controller communicates with the window, the supplementary air system, the exhaust system, The fire extinguishing sensor, the nozzle, and the fire extinguishing device are connected.
14. A method for extinguishing a fume cupboard, characterized in that it comprises:

    A fire source is detected in the working chamber of the fume hood;

    Control the window of the fume hood to move down and close along the height direction of the cabinet of the fume hood;

    Control the exhaust system of the fume cupboard to be in an open state, so that the working chamber of the fume cupboard is in a negative pressure state;

    The nozzles in the working chamber of the fume hood are controlled to spray the fire extinguishing agent to the working chamber of the fume hood.
15. The method for extinguishing a fume hood according to claim 14, wherein the fire extinguishing agent is perfluorohexanone.
16. The fire extinguishing method of the fume cupboard according to claim 14, characterized in that the fire extinguishing method further comprises: controlling the supplementary air system of the fume cupboard to be in a closed state, so that the working chamber of the fume cupboard is in a negative pressure state .
17. The fire extinguishing method of fume cupboard as claimed in claim 14, is characterized in that, a fire extinguishing sensor detects that the working chamber of fume cupboard has fire source, controls sound and light alarm to send alarm signal.
18. The fire extinguishing method of the fume hood according to claim 14, wherein at least two fire extinguishing sensors detect that there is a fire source in the working chamber of the fume hood, and control the nozzles to spray fire extinguishing agent into the working chamber of the fume hood.
19. The fire extinguishing method of the fume cupboard according to claim 16, characterized in that, the time for controlling the supplementary air system of the fume cupboard to be in the closed state is 60 seconds, and the time for controlling the exhaust system of the fume cupboard to be in the open state The time is 60 seconds.
20. The fume hood according to any one of claims 14 to 19, wherein the nozzle is controlled to spray out the fire extinguishing agent in the fire extinguishing device within 10 seconds.

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