Elevators were invented by Elisha Otis around 1854. Since then there have been many advances in terms of speed, motorization, energy efficiency, control, safety, but the fundamental concept of the elevator has not evolved. .It is still a cabin, suspended from cables, which moves vertically in a shaft, thanks to the winding/unwinding of the cables around a drum and a counterweight at the other end.This basic concept made possible the construction of high-rise towers.But faced with the development of towers over 500 m high, 1 km, or even 1600 m – the Mile-High Towers in development -, it shows significant limitations that constrain the designers of these very tall towers.The weight of the steel cables constitutes a severe limitation to the maximum height of vertical movements in elevators.KONE invented UltraRope, carbon fiber core cables that are lighter and more durable.©KONEUsing its UltraRope technology, KONE plans to achieve vertical travel of 800 m in height, while consuming significantly less electricity than braided steel cable technology.©KONEMinimize waiting timeOne of the problems in high towers is to minimize the waiting time for elevators, without increasing the number of cabins.A trick that has been used for 20 years is to create vertical zones of 10 to 20 stories.Each area is directly served by an elevator from the lobby of the building.For example, for a 40-storey building, two elevators will be used: the first serving floors 1 to 20, the second serving floors 21 to 40 with an express and non-stop route from the lobby to the 21st floor.For higher buildings, it is necessary to multiply the zones, therefore the elevator shafts.As a result, this method meets its limit from towers of approximately 70 floors which already require 4 elevator shafts.This method can nevertheless be extended beyond 70 floors by moving to two-level cabins, capable of carrying twice as many passengers.This is the model of the Eiffel Tower elevators.It has been used in American skyscrapers since the 1930s and can be applied without difficulty up to 90 floors.To go even higher, the designers split the tower into two buildings placed one on top of the other.A second lobby, often called "Sky Lobby" by the architects, on the 70th - 80th floor, is served directly by one or two elevators without stopping from the lobby at the entrance level of the building.Then the passengers change elevators and the vertical zoning method is applied again.This scheme – two buildings on top of each other – is suitable for up to 150 floors, with a few elevators capable of directly serving a height of 70 to 80 floors.KONE's UltraRope technology retains the usual components of an elevator system, but makes them considerably lighter.©KONEIntelligent Hall Call Destination DispatchingTo maximize the number of passengers per cabin and therefore contain energy consumption per passenger to an acceptable level, manufacturers have invented new elevator control algorithms.Called Intelligent Hall Call Destination Dispatching, this system appeared around 1992 with the Schindler Miconic 10 range.This consists of bringing together in the same cabin the passengers going to the same floor.This is achieved by asking each passenger to select their destination floor directly in the building lobby.The system subdivides each vertical zone into as many sub-zones as there are elevators serving this vertical zone.As demand increases, the number of floors in each sub-zone shrinks to increase capacity.When the demand decreases, the sub-zones overlap to reduce the waiting time.This system significantly increases the efficiency of the elevators, reduces the round trip time of each elevator, and therefore the waiting times for passengers, and makes it possible to reduce by 20 to 25% the number of elevators required serve a building.More space available for rent or saleAccording to Johannes de Jong, technical director of KONE, an elevator manufacturer, a 52-story office building was traditionally serviced by 24 cabins serving three vertical zones.The Intelligent Hall Call Destination Dispatching application allows the use of only 13 double cabins serving two areas.This eliminates 11 elevator shafts.This technique applies perfectly to the structure of a building on the other of 104 floors.It would take 13 cabins for the first building, 4 to 6 cabins to serve the Sky Lobby, then 13 cabins for the second building placed on top of the first.That is 30 to 32 elevator shafts in total, instead of 52 to 54. The reduction in the number of elevator shafts increases, on each floor, the surfaces available for rental or sale.MULTI from ThyssenKrupp does away with cables entirely, in favor of linear displacement motors, such as those used in magnetic levitation trains.©ThyssenKruppIntegration with access controlThe next step was the integration of elevator control with building access control.Most very tall buildings have several vertical zones: shops, gyms, crèches downstairs, then one or two hotels, then offices, for example.The integration of elevator control and access control limits passenger traffic to areas that are accessible to them and adds further optimization of elevator control and even better management of cabin movements.Naturally, each elevator manufacturer offers a different interface to connect to access control.Gateways – these automatons specialized in the translation between two protocols – are practically always necessary.Access control is most often available with a BACNet or BACNet/IP interface to which the lift operator's protocol must be connected.The gateway is generally provided by the lift manufacturer, because he alone controls his communication protocol.ThyssenKrupp built a 246m tower to test its MULTI concept and gain certification for Europe, Asian markets and North America.©ThyssenKruppHow to reduce cable weightThe intelligent management of lifts and their interfacing with access control does not solve everything.Despite the optimization of the number of elevator shafts and the displacement of the cabins, beyond 80 levels, the weight of the steel cables used for the traction of the elevators becomes a real obstacle, both technical and common sense. .From 100 floors, according to KONE, the weight of traditional braided steel cables reaches 50 to 70 tons per cabin.This results in significant energy consumption for simply moving the empty cabin.A cabin carries a maximum of 20 to 25 people at peak times, but can be used by a single passenger at off-peak times.To reduce the weight of braided steel cables, thus exceeding the 80-storey limit and reducing energy consumption, KONE invented UltraRope, a flat carbon fiber cable.According to the company, for an elevator performing a vertical travel of 500 m, UltraRope reduces the weight of all the moving masses of the elevator by 60%.Combined with the KONE EcoDisc engine – a permanent magnet synchronous motor – UltraRope technology reduces electricity consumption by 15% over a 500 m route.If the lift traveled 800 m, consumption would be reduced by 45%.UltraRope is a flat cable, the core of which is made of carbon fibres.The special coating reduces friction and eliminates the need for cable lubrication.Added to the fact that the life of UltraRope is twice as long as that of steel cables, the maintenance of the system is greatly reduced.The first building equipped with ThyssenKrupp's MULTI system will be delivered in Berlin in 2021. It is a 140-storey tower.©OVG Real EstateA technology that eliminates cablesThyssenKrupp has gone one step further and completely eliminated cables by adapting magnetic levitation motion technology to vertical runs.Baptized Multi, this first concept of cable-free elevator is based on linear displacement electric motors, initially developed for Transrapid, a magnetic levitation train.This solution offers the possibility of placing several cabins in the same shaft.It allows vertical and horizontal movements, the passage of a car from a horizontal movement to a vertical movement and vice versa.Crew cabs use carbon fiber for their walls and doors.This reduces their weight by 50% compared to conventional constructions.The safety of the cabins is ensured by the multiple propulsion and braking systems mounted on each cabin, as well as by the piloting preventing two cabins from getting too close in the same vertical shaft.ThyssenKrupp has built a 246 m high test tower, called Aufzugtestturm, for the Multi system in Rothweil, Germany.A first installation in a 140-storey towerIn this tower, operational since the end of 2016, the route of the cabins follows a loop: ascent, horizontal translation and descent.Multi has no intrinsic travel height limit, since in the absence of cables, only the weight of the cabin and its passengers is transported.The Multi technology will be certified for use in Europe in 2020, for North America (USA and Canada) in 2022.Multi's first installation will take place in East Side Tower Berlin, a project by Dutch developer OVG Real Estate.It will be a 140-storey tower, near the East Side Gallery in Berlin, built at a total cost of 400 million Euros and whose delivery is scheduled for 2021. Where traditional elevators occupy up to 40% of the surface of each floor in very tall towers, Multi will limit its footprint to 25% of the surface, leaving 75% of the surface available for sale or rental on each floor.One of the advantages of the Multi solution from ThyssenKrupp is to allow both vertical and horizontal movements.Architects, who design more and more towers with “Sky Bridges” or footbridges between two towers, should appreciate.©ThyssenKruppHow are towers over 500 m equipped today?Pending the generalization of these innovations, the tallest buildings in the world are today equipped with traditional elevators with vertical zoning and optimization of movements.The Burj Khalifa tower in Dubai, for example, which is the tallest building in the world at 829.8m, but with an occupancy height of only 584.5m, has 65 Otis elevators.Double cabin elevators directly serve the 124th and 125th floor observation decks in just 60 seconds, traveling at 10 m/second (36 km/h).An elevator also directly serves the last level at an altitude of 638 m, but a vertical travel height of only 504 m.Technicians are on site at all times and use a supervision built from Panorama to monitor all the operating parameters of the system.The installation was co-designed by specialist American design engineer Lerch Bates and Otis.The longest vertical journey in the worldLerch Bates has to his credit the design of "vertical displacement solutions" for 4 of the 8 towers over 500 m in operation in the world today, plus two others: one is abandoned, the other is search for funding.Mitsubishi Elevator currently holds the record for the longest vertical journey: 579.78 m in the second tallest building in the world, the Shanghai Tower (632 m in total height), with a displacement at 64.8 km/h for the emergency elevator.A total of 106 Mitsubishi elevators are installed in this tower and serve 5 different vertical zones, with direct access to the Sky Lobby from the 4 zones located above the "skirt" of the tower.In addition to their technology and the organization of their movements, elevators in very high towers raise other questions, in particular: can they participate in emergency evacuations in the event of a disaster or fire?This will be the subject of an article on security measures in these very tall buildings.In the meantime, our next article will deal with their structures and the way in which we compensate for the oscillating movements that the force of the winds imparts to them.The Shanghai Tower has no less than 106 single and double cabin elevators, supplied by Mitsubishi Elevator.©GenslerSource: batirama.com / Pascal PoggiEnter your Nickname (your comment will be published under this name)Enter your email (an alert will be sent to this address to notify you of the publication of your comment)Your comment will be published as soon as possible after validation by our moderators.© 2011 Batirama.com |produced by BIP Professional Information |Legal notices |ARTIDEVIS |ARTIPRIX |Notifications Update ARTIDEVIS V9