System and method for maintaining smokeless a vertical access connection of a multistorey building

Abstract

The invention relates to a system for keeping a vertical access passage (1) of a multi-story building smoke-free, comprising at least one vertical shaft (2) with at least two openings (21) and a pressurization system. Each opening (21) is suitable for connecting the shaft (2) to the vertical access passage (1) and has, on the one hand, a shaft opening (211) that opens into the shaft (2) and, on the other hand, a connecting opening (212) that is suitable for connecting to the vertical access passage (1). The shaft openings (211) of the openings (21) are arranged at different heights of the shaft (2), and the connecting openings (212) are suitable for arrangement at different heights of the vertical access passage (1). The pressurization system comprises at least one fan unit (3) for each opening (21) by which air can be conveyed from the shaft (2) into the vertical access passage (1).The invention also relates to a method for keeping a vertical access connection (1) free of smoke.

Description

[0001] The present invention relates to a multi-story building with a system for keeping a vertical access connection of the multi-story building free of smoke by means of positive pressure ventilation according to claim 1 and a corresponding method for keeping a vertical access connection of a multi-story building free of smoke according to claim 8.

[0002] Buildings with more than one story are equipped with at least one stairwell that provides access to the various floors. In the event of a fire, this stairwell becomes an escape and rescue route and is therefore designed as a stairwell with an airlock (safety stairwell), which must be kept smoke-free. For this purpose, smoke protection pressurisation systems (positive pressure ventilation systems) are used that draw outside air into the stairwell, thus pressurising it. This positive pressure prevents smoke from entering the stairwell via leaks, for example when doors are closed (pressure criterion), or when the door between the stairwell and the fire floor is additionally opened, allowing air to flow through this door (flow criterion). State-of-the-art smoke protection systems are used to provide access to the building with a central smoke protection pressurisation system, which is typically located on the ground floor or basement of the building, close to the relevant outside air intake.The airflow generated by the smoke protection pressure system is then directed into the stairwell via horizontal supply air ducts and vertical shafts. It is known in the prior art to arrange multiple air outlets at different locations in the stairwell, for example, an air outlet every third floor, or even on every floor, with each air outlet equipped with a supply air element or, in addition, a controllable damper. In this way, air from the smoke protection pressure system can be introduced to specific locations in the stairwell, in particular to the fire floor. A high-rise building with such a system is described, for example, in DE202015009604U1 and DE20113242U1. A disadvantage of the known systems is that high-rise buildings require powerful central smoke protection pressure systems, which often have to be housed in separate rooms because they require a lot of space.In addition to the loss of space, another disadvantage is that if the only central smoke protection pressure system fails, keeping the escape and rescue routes smoke-free is no longer guaranteed. Another disadvantage is that such central smoke protection pressure systems are very slow to respond, as they require large changes in volume flow, which is also very demanding from a control engineering perspective. They are therefore not ideally suited for dynamic, real-time adaptation to the conditions in the escape and rescue route.

[0003] KR20180109269A discloses a multi-story building with an elevator shaft that has an opening to the premises on each floor. Each opening is provided with a fan that can transport air from the elevator shaft to the premises. KR 2018 0109269 A discloses a multi-story building according to the preamble of claim 1.

[0004] The present invention now has the object of providing a reliable, space-saving, flexible and high-performance system for keeping a vertical access connection of a multi-story building smoke-free.

[0005] This object is achieved by a multi-story building with a system for keeping a vertical access connection of the multi-story building smoke-free with the features of patent claim 1 and a method for keeping a multi-story building smoke-free according to claim 8.

[0006] Further features and embodiments emerge from the dependent claims and their advantages are explained in the following description.

[0007] The drawings show: Figure 1 Multi-story building with a smoke control system according to the present invention. Figure 2a and 2bMulti-story building according to the present invention, wherein a method for keeping smoke free not covered by the invention is used. Figure 3 Multi-story building according to the present invention, wherein the inventive method for keeping smoke free is used. Figure 4 Fan unit Figure 5 Fan with flap

[0008] The figures represent possible embodiments, which are explained in the following description.

[0009] The multi-storey building according to the invention comprises a vertical access connection (1) which represents a connecting route between at least two floors.

[0010] The vertical access connection 1 allows users to access the various floors of a building and is, for example, a stairwell or an elevator shaft. The building according to the invention comprises at least one vertical shaft 2 with at least two passages 21 and a pressurization system ( Figure 1). Each passage 21 is suitable for connecting the shaft 2 to the vertical access connection 1 and has, on the one hand, a shaft opening 211 that opens into the shaft 2 and, on the other hand, a connecting opening 212 that is suitable for connection to the vertical access connection 1. The shaft openings 211 of the passages 21 are arranged at different heights of the shaft 2, and the connecting openings 212 are suitable for arrangement at different heights of the vertical access connection 1. The pressurization system comprises at least one fan unit 3 for each passage 21, with which air can be conveyed optionally from the shaft 2 into the vertical access connection 1 or from the vertical access connection 1 into the shaft 2.Each fan unit 3 is individually and independently controllable from the other fan units 3 and can move air in both directions (not simultaneously, but selectively in one or the other direction). Furthermore, the lower section of the shaft 2 is connected to an outside area of ​​the building via an air inlet 22, either directly or via a duct, so that outside air can enter the shaft 2 through the air inlet. This air inlet 22 can be equipped with flaps or fans if necessary to close, control, or promote the passage of air. It is advantageous if the shaft 2 has a low aerodynamic impedance between the shaft openings 211 to ensure unhindered air movement in both directions within the shaft 2.This can be achieved by a uniform, for example round or square, diameter of the shaft 2 and by the absence of obstacles in the shaft 2. In particular, the shaft 2 is not an elevator shaft in which an elevator car is located and in which, depending on the position and / or movement of the elevator car in the elevator shaft, the vertical movement of the air is severely impaired. Rather, the shaft is an additional shaft for the purpose of air conveyance and distribution in the vertical access connection 1. It is advantageous if the building is provided with a vertical ventilation duct 4 with air outlets 41 through which air can escape from the building. The air outlets 41 are preferably arranged on each floor and in the room immediately adjacent to the vertical access connection 1. Additionally or alternatively, air can also flow out of the building via other routes, for example via an open facade.

[0011] According to the method according to the invention, in the event of a fire, the fire floor is identified and a first fan unit 3, which is located near the fire floor, is put into operation in such a way that air is conveyed through a first passage 21 from the shaft 2 into the vertical access connection 1 ( Figure 2a ). This creates a defined overpressure in the vertical access connection 1 in the area of ​​the fire floor. Due to this overpressure, when the door between the vertical access connection 1 and the burning area is opened, an air flow is created from the vertical access connection 1 through this door to the air outlet 41 of the ventilation duct 4 ( Figure 2b). This air flow blows the smoke coming from the burning area away from the door to the vertical access connection 1 and transports the smoke via the ventilation duct 4 or via other outflows (open facade) outside the building. The entry of smoke into the vertical access connection 1 is thus effectively prevented. In contrast to the prior art, in which a single large smoke protection pressure system is used and the introduced air is directed to the fire floor by means of, for example, controllable flaps, the invention provides for several smaller independent fan units 3 which are specifically activated to generate an overpressure in the desired area of ​​the vertical access connection 1 under the simultaneous influence of disturbing variables such as thermals, open doors, etc.The advantage of this is that the fan units 3 can generate the same overpressure in the stairwell and on the fire floor with a lower power output as a central smoke protection pressure system, and that no space is required for a bulky central smoke protection pressure system. Identification of the fire floor can be achieved using any conventional, state-of-the-art method, including fire sensors, etc.

[0012] According to the method according to the invention, it is also provided that in the event of a fire, at least one first fan unit 3, which is located near the fire floor, is put into operation in such a way that air is conveyed through a first passage 21 from the shaft 2 into the vertical access connection 1 and at least one supporting fan unit 3, which is remote from the fire floor, is put into operation in such a way that air is conveyed through a second passage 21 in the opposite direction from the vertical access connection 1 into the shaft 2 ( Figure 3). This creates overpressure in shaft 2 in the area of ​​the second opening 21, which quickly spreads due to the unhindered air movement in shaft 2, and the entire shaft 2 is thus pressurized. This overpressure supports the first fan unit 3 and amplifies the air flow through the first opening 21 and the overpressure generated in the vertical access connection 1 in the area of ​​the fire floor. This also equalizes the pressure conditions in the access connection 1 compared to shaft 2. The first and the supporting fan unit 3 therefore work together, and their outputs are added together. By switching on additional supporting fan units 3, the overall output of the pressurization system can be continually and flexibly increased. This results in a swarm effect, according to which individual small units work together to achieve a powerful overall effect.The invention thus has the advantage over the prior art that a large number of small fan units 3 can be used, which are inexpensive, more compact, and easier to install than a large, central smoke protection pressure system. Tests have shown, for example, that fan units 3 with an output of approximately one-quarter to one-third of the output of a conventional smoke protection pressure system are well suited. There are also advantages in terms of maintenance and the replacement of individual fan units 3. Each small fan unit 3 is also much more reactive and can be started up more quickly than a sluggish central smoke protection pressure system in order to create the desired overpressure locally and with immediate effect. The system is therefore particularly well suited for dynamic, real-time adjustment in response to sudden changes in the vertical access connection 1 (opening / closing of a door, etc.).Of course, each supporting fan unit 3 near the corresponding connection opening 212 also creates a local pressure drop in the vertical access connection 1. However, this cannot compensate for the overpressure generated by the first fan unit 3, not even partially, because vertical access connections 1 such as stairwells and elevator shafts have a high aerodynamic impedance. In stairwells, the zigzag arrangement of the staircases makes air movement between two floors of the stairwell 1 difficult. In elevator shafts, the elevator car can also severely impair the vertical movement of the air depending on its position in the elevator shaft. The planned relative pressure drop in the stairwell 1 created by a supporting fan unit 3 therefore remains local and is partially even compensated for by leaks through the surrounding doors.

[0013] According to the invention, the vertical access connection 1 is connected to the shaft 2 via a passage 21 on several floors, preferably on each floor, and each passage 21 is provided with its own fan unit 3. In this way, in the event of a fire, the stairwell can be pressurized directly and precisely in the desired area by activating the corresponding fan unit 3. This also ensures the high reactivity of the system: In the event of a sudden pressure drop in the vertical access connection 1, for example, when the door to the fire floor is opened by escapees, the corresponding fan unit 3 can restore the desired overpressure locally and with immediate effect.

[0014] To support the fan unit 3 of the fire floor, several additional fan units 3 from additional passages on adjacent floors, for example those on the floors above and / or below, can be activated in such a way that the vertical access connection 1 is pressurized over a larger area near the fire floor. If the fire floor is the top floor, in addition to the fan unit 3 on the top floor, for example, the fan units 3 of the passages on the two floors below can also transport air through the respective passage 21 from the shaft 2 into the vertical access connection 1. If the fire floor is the lowest floor, in addition to the fan unit 3 on the lowest floor, for example, the fan units 3 of the passages on the two floors above can also transport air through the respective passage 21 from the shaft 2 into the vertical access connection 1.In addition to these fan units 3, which convey air from the shaft 2 into the vertical access connection 1, one or more further fan units 3, for example all other fan units 3 of the building, can convey air through the respective passages 21 from the vertical access connection 1 into the shaft 2, as already described above.

[0015] Furthermore, it can be advantageous if the fan units 3 of two or more directly adjacent floors do not counteract each other, i.e., one fan unit 3 does not convey air from the shaft 2 into the vertical access connection 1 while the other conversely conveys air from the vertical access connection 1 into the shaft 2. The fan units 3 of two or more directly adjacent floors would be so close to each other that their effects would virtually cancel each other out. To avoid this, it is advantageous to have one or more neutral, non-acting fan units 3 between two opposing fan units 3.Furthermore, to prevent the pressure generated in the vertical access connection 1 or in the shaft 2 from escaping through the passage 21 of a non-acting fan unit 3, it is particularly advantageous if each fan unit 3 is provided with a controllable damper with which the corresponding passage 21 can be closed in such a way that no air can pass between the shaft 2 and the vertical access connection 1. It is therefore advantageous if the damper of a neutral fan unit is closed. The damper or the control of the fan speed can also be used to regulate the performance of the fan unit, e.g. to generate a somewhat lower overpressure in the floor above and below the fire floor or, in the case of a very tall building, only a defined number of fan units are activated, depending on the fire floor or other criteria.The flap can be designed in a variety of ways and has, for example, a series of louvre-like slats 32 arranged next to one another, which can be pivoted between an open and a closed position (. Figure 5 ). Such a flap can further increase the reaction speed of the fan unit, since opening and closing the flap is much easier and faster than increasing and decreasing the fan speed.

[0016] A fan unit 3 may comprise one or more fans 31. In the preferred embodiment of the invention, a fan unit 3 comprises a plurality of fans 31 arranged side by side (see Figure 4). The provision of a fan unit 3 with several small fans 31 is preferred because it would still be partially operational even if individual fans 31 failed and is therefore very reliable. A fan unit 3 with a single fan 31, on the other hand, would no longer be operational at all if this single fan 31 failed. The fans 31 can all be connected in parallel or can be controlled individually. In embodiments of the invention with a flap, it can be advantageous to provide each fan 31 with its own flap. If only a slight overpressure is to be generated in the vertical access connection 1, only certain fans 31 of the fan unit 3 could be operated, with their flaps opened while the flaps of the other, neutral fans 31 are closed. Alternatively, the speed of the fans 31 can also be adjusted.Individual flaps per fan 31 are also advantageous so that they can be closed specifically if there is a malfunction of the corresponding fan 31.

[0017] In the preferred embodiment of the invention, the pressurization system comprises at least one pressure sensor for controlling / regulating the pressurization system. It is particularly advantageous if each fan unit is provided with a sensor for determining the pressure difference between the vertical access connection in the area of ​​the corresponding connection opening 212 and / or the outside area of ​​the building and / or the stairwell or the airlock or the usable areas. The performance of the fan unit, the flap and the individual fans can be controlled according to a predefined setpoint and based on the determined pressure difference or based on another controlled variable, for example, depending on a door position (for example by controlling the speed of the fans, by adjusting the air flow direction and / or by actuating flaps). The predefined setpoint can, for example,can be selected from a predefined list of setpoints suitable for different situations, e.g. outside temperature, time of year. One of these situations is, for example, when the fan unit is located on the fire floor. In this case, the setpoint corresponds to the overpressure to be achieved on the fire floor. Another situation is, for example, when the fan unit is located on a floor adjacent to the fire floor. In this case, the setpoint can, for example, be lower than the overpressure to be achieved on the fire floor. To quickly build up the desired overpressure when starting the pressurization system, all fans 31 of a fan unit 3 can, for example, be activated.Once the desired overpressure is reached, only a portion of the power of the fans 31 of the fan unit 3 is required to maintain the overpressure, so that some of the fans 1 can be switched off, or the speed of certain fans 31 can be reduced, or the associated flap can be completely or partially closed. The pressure in the vertical access connection 1 can then still vary, in particular if a door of the vertical access connection 1 is opened, causing air to quickly escape from the vertical access connection 1. To maintain the desired overpressure, additional fans 31 can be dynamically switched on or off depending on the desired flow direction, and / or individual flaps can be opened and closed more or less.

[0018] A central controller can be provided to control the pressurization system, or the fan units 3 can communicate with each other and operate in a coordinated manner. This is particularly advantageous because the fan units 3 are then not dependent on a controller and can operate autonomously. Each fan unit 3 could be able to communicate with all other fan units 3 or only with the neighboring fan units 3. In the latter case, communications could propagate from fan unit 3 to fan unit 3. In an advantageous embodiment, each fan unit functions autonomously according to predetermined setpoints, so that they only receive an instruction when a fire signal is triggered, for example, which triggers the start-up of the fans and specifies the selection of the appropriate setpoint depending on the operating mode and the control system.

[0019] Since the fan units 3 are distributed within the building and not housed in separate rooms on the ground floor or basement of the building as in the prior art, the noise generated thereby poses a problem, which must be controlled: According to applicable standards, the noise generated by a fan unit 3 must not exceed 80 dB(A) at the fire department control station. To overcome this problem, an advantageous embodiment of the invention provides for one or more fan units 3 to be provided with soundproofing, which serves to dampen the noise generated by the fans. This is achieved, for example, by optimizing the speeds and / or louvers 32 in front of the fan unit 3.

[0020] The passages 21 can be designed differently depending on the embodiment of the invention. In particular, they do not need to have a minimum length and can also be simple openings if the shaft 2 and the vertical access connection 1 are located directly adjacent to each other.

[0021] In winter and summer, large temperature differences can occur between the interior and exterior of the building, resulting in spontaneous ascending or descending air currents in the vertical access connection 1. In summer, the interior air of the building is generally cooler than the exterior air, resulting in a descending air current in the vertical access connection 1, and therefore also a higher pressure in the lower area of ​​the vertical access connection 1 than in the upper area. Conversely, in winter, the interior air of the building is warmer than the exterior air, resulting in an ascending air current in the vertical access connection 1, and therefore also a higher pressure in the upper area of ​​the vertical access connection 1 than in the lower area.These thermally induced flows and pressure differences in the vertical access connection 1 can be exploited and support the pressurization system if they occur in the correct direction. Otherwise, the pressurization system must be able to counteract and compensate for these flows to ensure the desired smoke protection effect.

Claims

1. Multi-storey building with a system for keeping a vertical access (1) of the building free of smoke, comprising at least one vertical shaft (2) with at least two passages (21) and a pressurization system, wherein each passage (21) connects the shaft (2) to the vertical access (1) and has on one hand a shaft opening (211) which opens into the shaft (2) and on the other hand an access opening (212) which is connected to the vertical access (1), wherein the shaft openings (211) of the passages (21) are arranged at different heights of the shaft (2) and the access openings (212) are arranged at different heights of the vertical access (1), wherein the vertical access (1) is connected to the shaft via a passage (21) on several floors, wherein the pressurization system has at least one fan unit (3) for each passage (21) with which air can be conveyed from the shaft (2) into the vertical access (1), characterised in that at least one fan unit (3) is also able to convey air from the access (1) into the shaft (2) and can be controlled to convey the air either in one direction or the other.

2. Building according to claim 1, characterised in that each fan unit (3) can be controlled individually and independently of the other fan units (3) and can convey air in both directions.

3. Building according to claim 1, characterised in that the shaft (2) has a passage for connection to the vertical access (1) for each floor of the building.

4. Building according to claim 1, characterised in that a fan unit (3) has a plurality of fans (31) arranged next to one another in the same plane.

5. Building according to claim 1, characterised in that a fan unit (3) is provided with a controllable flap with which the passage (21) can be closed in such a way that no passage of air can take place between the shaft (2) and the stairwell (1).

6. Building according to claim 5, characterised in that the flap has a series of slats (32) arranged next to one another, which can be pivoted between an open and a closed position.

7. Building according to claim 1, characterised in that a fan unit (3) is provided with sound insulation which serves to dampen the noise generated by the fans (31).

8. Method for keeping a vertical access (1) of a multi-storey building according to claim 1 free of smoke in the event of a fire, characterised by the following steps: • the floor which is on fire is identified; • a first fan unit (3) located near the floor which is on fire is put into operation such that air is conveyed through a first passage (21) from the shaft (2) into the vertical access (1); and • in addition to the first fan unit (3), at least one supporting fan unit (3) located away from the floor which is on fire is put into operation such that air is conveyed through a second passage (21) from the vertical access (1) into the shaft (2).

9. Method according to claim 8, characterised in that between two fan units (3) operating in opposed directions, there is at least one neutral, non-acting fan unit (3), this neutral fan unit (3) is provided with a controllable flap with which the corresponding passage (21) is closed such that no passage of air can take place between the shaft (2) and the vertical access (1).

10. Method according to claim 8 or claim 9, characterised in that pressure changes in the vertical access are detected and the power of the pressurization system is adjusted in response thereto by dynamically switching fan units (3) on or off and changing the volume flows.

11. Method according to claim 8, characterised in that in winter and summer, the pressurization system counteracts the spontaneous, thermally induced air flow prevailing in the vertical access (1).

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