Centralized fire alarm systems, warning and fire extinguishing systems at geographically distributed facilities.
High-rise construction is a hot topic. Russian megacities are growing upward, new requirements for life support and safety systems for skyscrapers are being developed, and integrators share their experience of truly complex work on equipping high-rises with various engineering systems on the pages of industry publications. Such popularity has somewhat pushed into the background the topic of building territorially distributed facilities with a single infrastructure and centralized fire safety systems, such as fire alarms, notification, fire extinguishing, etc. Meanwhile, the share of such facilities, both newly erected and modernized, significantly exceeds the volume of high-rise construction. Distributed facilities include logistics centers, factories, cottage villages, residential neighborhoods, and even large hypermarkets. In general, all those facilities whose infrastructure is distributed over a fairly large territory, but functionally united into a single control center.
Features of building systems on distributed facilities
The problems that installers may encounter when equipping distributed objects are largely a consequence of the features of the objects themselves. It is clear that the main one is their location on large areas, when individual rooms or even buildings can be located from hundreds of meters to tens of kilometers apart. As a result, it is impossible to implement a fire alarm and notification system on such objects based on controllers that have only a centralized design principle. The reason: the limited data transmission distance of communication lines and loop lines. For example, loop lines in most fire alarm systems are from 1 to a maximum of 3 km, and this loop length decreases proportionally to its load of system elements. Whereas the length of all loops on a distributed object can reach 20 or even more kilometers.
Another problem of building fire safety systems for such facilities is that each functionally complete building must function independently of other buildings and at the same time be part of the overall security system of the entire facility, i.e. be monitored and controlled from a single control center. Such functionally complete buildings within distributed facilities can be, for example, a house in a microdistrict, a cottage in a village, a warehouse in a logistics center, a production building of a plant, a hypermarket store, etc. A striking example of such a situation is equipping one of the large hypermarkets with a fire alarm system. In this case, each large tenant of this complex has a separate fire alarm panel that ensures fire safety for the territory of this tenant. Each panel is connected to others via a network, which made it possible to implement fire safety for the entire complex as a whole and output the necessary information from the entire complex to the central control center.
When implementing such a system, it is also necessary to take into account the fact that buildings in a distributed complex can be built and commissioned in stages, so the highest level of any good system is its ability to function both in a separate (unfinished) form and in a complex.
Methods for resolving technical problems at distributed facilities
From all of the above it is clear: modern fire alarm and notification systems must have a distributed structure of construction. This is the most effective way to ensure fire safety of a complex of distributed objects. At the same time, information from all functionally complete sub-objects must be output to a single control center of the complex. This characteristic feature is possessed by systems built on a modular principle, such as Simplex, Esser, Schrack, etc.
The main idea of such systems is their universality and expandability. As a rule, in the process of implementing a distributed facility, separate system controllers are installed on each of the functionally complete buildings, from which fire alarm and notification loops are laid. Then all system controllers are combined into a single inter-station network, and a system monitoring station is installed in the central control center.
A very important characteristic of the system used in this case is the maximum permissible loop length. The longer it is, the larger the area we can cover with one loop. For example, Esser and Siemens fire alarm systems provide a loop length of up to 3 km, which allows them to cover larger spaces with sensors using fewer wires.
If the buildings of a large distributed complex are spread over significant distances, it is necessary to take into account such a parameter as inter-station communication, i.e. the maximum possible distance between fire alarm panels in the network. For example, Simplex fire panels can be separated from each other by up to 32 km via an optical communication channel. In addition, they have the ability to communicate via TCP/IP. This allows the implementation of a fire alarm system for maximally distributed objects. This capability became necessary when implementing a fire safety system for one of the plants, whose buildings are distributed over a vast area of up to tens of hectares.
Another parameter that influences the choice of a system for installation at a distributed facility is the maximum capacity of each controller, i.e. how many devices can be connected to each individual controller in the network. This parameter influences the degree of distribution of the system. For example, the maximum capacity of each individual controller of the Bolid addressable fire alarm system is 127 devices, which is ideal for implementing a fire alarm system, say, for a cottage village or a number of small buildings. In this case, the system is organized according to the principle: one controller per house with subsequent transmission of signals to the central control center. And such controllers as Simplex, Esser, Bosch, with a capacity of up to 2000-4000 devices, are more appropriate to use to ensure fire safety of larger facilities, for example, residential areas, factories, hypermarkets.
Construction and equipment of a distributed facility with security systems is partly akin to similar work on a high-rise facility. Because a distributed facility is a high-rise building laid on the ground. And there are a lot of such facilities being built in Russia. Fire safety of such an object is no less a complex technical task than the design and installation of a similar system in a high-rise building. Correct organization of the fire safety system (FSS) at an object of this class, maximum consideration of all its features allows not only to implement a reliable and effective system, but also to significantly reduce material costs for cable laying, commissioning and operation of the system.