Wednesday, January 5, 2011

【 Weak current college 】 building automation system construction problems 】

Summary: intelligent buildings is the inevitable outcome of the information age, intelligent building weak electricity system implementation, become the automation and control areas is an important branch, will be built into a modern building with international advanced level of smart buildings and maintain further scalability is automatic control engineering and technical personnel, an important issue.

Remember my earliest contact smart buildings are graduated, my graduation thesis title is the residential security system design ". Pass the graduation design makes me intelligent buildings have a certain understanding, the so-called intelligent architecture that is electronic technology, sensor technology, network technology, building up the building to meet people's needs. In postgraduate study phase, a roommate in Zhejiang Province bidding Bureau, responsible for the intelligent building of the bid, plus I am more interested in intelligent buildings, so have the opportunity to learn a lot of intelligent building, and practical applications to intelligent building weak electricity project design process has a certain understanding. This time I see your recruiting intelligent building direction of teacher, I was interested in his hometown of education, so I hope to be able to apply to become a teacher in your school. Following my personal understanding of the intelligent building, on the development of intelligent building some of nature's introduction.
Intelligent building is the inevitable outcome of the information age, is a high-tech and unique combination of modern architecture. The world's first building intelligent building in 1984 in the United States, then in Europe, America, Japan and all over the world thrive, from early 1990s introduced intelligent building, then get rapid development. According to statistics, recently built in China will account for a large building, half of the world and into the mainstream of modern large building is the intelligent buildings, intelligent building weak electricity system implementation, become the automation and control areas is an important branch, will be built into a modern building with international advanced level of smart buildings and maintain further scalability is automatic control engineering and technical personnel, an important issue.
Building intelligent engineering including: 1, computer management systems; 2, building equipment automation systems engineering; 3, security monitoring and alarm system; 4, smart card systems engineering; 5, communication systems engineering; 6, satellite and sharing of television systems engineering; 7, garage management systems engineering; 8, cabling systems engineering; 9, computer network systems engineering; 10, broadcast system engineering; 11, conference-systems engineering: 12, video-on-demand system engineering; 13, intelligent community integrated property management system project; 14, Visual meeting system engineering; 15, large-screen display systems engineering;

1. intelligent building weak electricity system design
1.1 intelligent buildings feature has the following characteristics: a safe, healthy, comfortable and effective work environment. Flexibility, the design-time can have different flexibility to meet changing customer requirements. Save regular operation and maintenance needs. You can fit the needs of future development.
1.2 intelligent building design considerations: field controller itself should be set to all functions, once the system is out of control, or a network problem occurs, the site controller is still guaranteed to run, improve overall system reliability. Modular hardware design, can be effectively distributed intelligent systems and equipment throughout the building, and each device has a certain degree of adaptability to meet the environmental requirements, in order to play each device's maximum control. System design should be open. To meet the market on a variety of software and hardware interface standard that enables the exchange of information between the various systems of obstacles. System design should be oriented to the user, make it easy for users to operation, convenient maintenance, operating costs to a minimum and will repair system downtime is minimal.
1.3 intelligent building weak electricity system structure: intelligent building weak electricity system generally includes the following subsystems: building automation management subsystem (BAS), fire auto-alarm system (FAS), a security monitoring system (CCTV), satellite and cable television (CATV) subsystem, underground garage management subsystem (CPS), public broadcast and emergency broadcasting system (PAS), programmable switch subsystem (PABX), structured cabling system (PDS) in the building automation management subsystem in often contains access control subsystem and burglar alarm system. Intelligent building various subsystems for building offers all kinds of electrical and mechanical equipment monitoring and management, for building the user creating safe, healthy, pleasant and productive working environment, providing a modern means of communication and Office conditions, meet a variety of users on a different environment, functional requirements.

2 intelligent building weak electricity system subsystems
2.1 building automation management subsystem (BAS) building automation management subsystem is the intelligent building weak electricity system core, it's high reliability is high reliability of the whole electronic system and, therefore, the cornerstone of BAS system take three-level control. Action station level composed by computer and printer, using real-time graphical monitoring operations software is BAS system for human-machine interface, you can display or print information to observe the current or previous system and monitoring the health of various mechanical and electrical equipment and data, accessible through the keyboard or mouse action to change the operation of various mechanical and electrical equipment, so as to achieve a specific monitoring requirements.
Network controller level
Network controller is BAS system communication network of important device, is also the heart of the entire BAS system. It on the one hand, via Ethernet and action points and other network controller, on the other hand via the fieldbus networks and distribution in the building, all direct digital controller communications. In the network controller to hold all the information for the entire system, the network controller with a variety of control functions, such as a variety of electromechanical equipment uptime statistics, events, statistics, load peak limit load calculation, linkage control, unit group control and other complex high-performance control functions on the BAS system for systematic monitoring. At the same time, the network controller and each subsystem access BAS system facilities integration of important interfaces.
Site controller level
Department of field controller componentsCommission of the third level, its main function is to receive installation to all types of electrical equipment on a variety of sensors, detectors, as issued by the data controller within the parameters set in advance and advance preparation of control program for the corresponding operation (such as PID, Max, delay, etc) and of the various types of equipment for control, at any time in accordance with the operator station via network controller issued instructions to adjust the parameters or start the procedure to change or start the appropriate device monitoring.
A three-level control of the features are as follows:
System of three-level control uses a decentralized control, centralized management structure, even if the system is part of your network damage control or line, the only system of this part of the paralysis, not affect the operation of the entire system. At the same time, the field controller with industrial grade components and have independent run function, even if the operator station or network problems do not work, the site controller will still be able to press the controller internal pre-set parameters and advance preparation of control programs continue to run, the system will still be able to run. A three-level control of structure, so that each layer of the structure is relatively simple, and reduce the complexity of the repair, at the same level of network for 10 Gigabit Ethernet, the secondary network to 9600 baud RS-485 bus, reduces the system network, especially the scene environment introduced the possibility of interference. Building automation management system monitoring the building all the electromechanical equipment such as hot and cold source units, air handling units, air supply unit, VAV, drainage, ventilation, and distribution, lighting, elevators, etc.
Hot and cold source unit:
Modern cooling and General to freezer, heat pump, with a variety of pumps, cooling towers, butterfly valve, the water level switch, thermometer, flow meters, etc.
Cooling system is a building in the heart of the HVAC system, is also a large energy-consuming, control requirements are also high, their general monitoring: unit operation parameters: including the start-up and shut-down state of the unit, fault alarm, for water temperature and flow, the water pump start-up and shut-down status, fault alarm. Backwater duct pressure differential telemetry and control. According to the given time program switching units, pumps, cooling towers, butterfly valve and so on. According to the cold/heat load to determine the required number of initiated units, unit group control. Air conditioning unit:
Unit operation parameters: include/air temperature, humidity, filter clogging status, fan status and overload alarm. According to the given time program and stopping fan. According to the temperature control air conditioner water valve to open degree. Water valves and blower interlocking movement. Air supply unit: unit operation parameters: temperature, including import and export filters blocking status, fan status and overload alarm. According to the given time program and stopping fan. According to the temperature regulating new fan water valve to open degree. VAV: monitoring terminal device of temperature and air flow. According to the given time program and stopping fan. Control of the terminal device of damper angle. Drainage monitoring: monitors various water tank of high and low level and alarm. Monitor various pump running and overload alarm.
According to the parameters required to control water pump stops. Send/exhaust fan monitoring: monitor sent/exhaust fan running and overload alarm. By the time the program control fan stops. Distribution Watch: watch high/low-voltage electrical parameters, including voltage, current, frequency, active power, reactive power, power factor, etc. Monitor switch cabinet contactor operation status and fault alarm. Watch Transformers temperature and fault alarm. Lighting control: monitor the operational status of the lighting circuit. By the time the program control selected circuit closing the main contactor. Elevator monitoring: monitors the status of the elevator and fault alarm.
2.2 fire auto-alarm system (FAS)
Fire auto-alarm subsystem uses intelligent smoke sensing probes and temperature-sensing probes to intelligently induction of smoke and heat, give the appropriate analog values, through advanced algorithms that can cause the system to distinguish between true and false alarm. System display capable of graphical displays the exact locations and fire alarm properties. Fire alarm after confirmation, the system can automatically issue the appropriate fire emergency broadcasting and fire control, for the safe evacuation of staff and the correct and effective fire fighting. Fire auto-alarm subsystem typically include control host, emergency broadcast control unit, fire phone control unit, color graphic display unit, regional display/control panel and intelligent smoke, temperature probe, intelligent monitoring, control module, etc. Fire auto-alarm subsystem design of automated monitoring, in accordance with the norms of fire in buildings within a certain space layout smoke detector or temperature sensing probes, and according to probe the environment set up the appropriate detection sensitivity. These smoke, temperature sensing probes are engraved and detection with building smoke, temperature, beginning as soon as the fire, you will promptly be fire signal transmission to the fire Centre. In accordance with the fire code, in a building in some public places in arrangement of manual alarm, monitoring module links to alarm circuit, when people find that the fire alarm is triggered, the alarm signal is transmitted to the fire control centre.
Fire auto-alarm subsystem of linkage control design
Water spray system: in building each layer water fire mains water flow switch on the set, when the floor in a a water spray head due to overheating and action on the water, the water flow, switching action and its adjoining monitoring modules will signal transmission to the fire Centre, in order to prevent "water hammer" effect caused by the flow switch malfunction, this signal will not start spraying equipment, only when wet alarm valve at the action, the system will start spraying pump, in order to protect the fire-fighting water supply. Fire suppression system: when the system receives a broken glass Manual alarm alarm signal and confirmed, the system starts the fire pump.
Smoke control system: when the system recognizes immediately after the fire occurred on building exhaust fan, and opened fire on the lower level and the exhaust valve, the ignition on, the lower layer and the flue. Positive pressure ventilation system: when the system recognizes immediately after the fire occurred on building positive pressure ventilator, and opened fire on the lower layer and its air supply valve, the stairs passage, prevent flue gas pressure, guarantees when the evacuation escape. air safety Fire broadcasting system: when the system after the confirmed outbreaks of fire, the system automatically cut off background music broadcasting and receiving on fire layer and its upper and down to the speakersFire evacuation of broadcasting to guide. Elevator landing system; when the system after the confirmed outbreaks of fire, the system immediately forced all elevators to the first floor, and automatically cut off the passenger elevator, the freight elevator, Elevator only reserved for firefighters and fire. Shutter control: when fire channel roll-front sides of the smoke detector alarms, the system will control the shutter down to the ground 1. 5 metres, so that staff can be evacuated when the shutter on either side of the temperature sensor probe alarm time, the system control shutter fell to the ground to complete fire protection district. Other linkage control: when the system recognizes that there is a fire, the system automatically ring fire layer and its upper and down alarm/Flash, draw attention to the timely evacuation, the system will automatically shut off the fire floor and upper and down of non-fire power.
2.3 security monitoring subsystem
Security monitoring system consists of CCTV surveillance systems, access control and patrol system and anti-theft alarm system. CCTV monitoring system by building entrance, Hall, important channel, elevator and elevator Hall, garage and other places to set the camera, on the main regional building internal and important part of monitoring and control, you can visually grasp of the situation and record event facts, identify and avoid possible unexpected event, as building security and management provide a factual basis. System control hosts a powerful control, operation, functionality, not only can matrix switching images, but also issues various alarm information alarm linkage function. System configuration for long video, will all be video signals for the subsequent query incident.
Access control system to an open distributed system, through the building management monitoring center, computer center, financial sector, equipment rooms, and other important regional implementing channel control, for seamless security management, enabling powerful complete access control and management functions. Systems through communication lines and various intelligent access controller and elevator controllers are connected, you can control the cardholder access time restrictions and regional restrictions, distributed intelligence is the importers control system structure characteristics, regardless of any communication problem occurred, and the access controller can still implement regional control, time control. Electronic patrol system that both sides of the floor and the staircase and the signal line patrols to check, set up electronic patrol, patrol officers in the press line inspection at each checkpoint by a cixun more buttons or swipe card, the system immediately record button/card action time so faithfully recorded the patrol, to enhance security on duty management provides informative data. When the patrol officers too early, too late or not sequentially patrol or not patrol a patrol station, System host immediately issued an alert signal, so that the control centre of the guards to take corresponding measures according to the situation.
Burglar alarm system in the building's first floor, the basement floor of the entrance, an important place within the set alarm detector and alarm buttons, when there is unlawful, illegal intrusion prevention area, the detector will immediately transmit alarm signals to a monitoring center. Burglar alarm system alarm linkage function, when the alarm signal, closed circuit television monitoring system will start the appropriate camera camera, Security Center's primary monitor screen also synchronous tracking the camera signals; building automatic control system opens illegal intruder which channel of lighting, and close the doors, the illegal intrusion, siege in the region, thus effectively protecting the building personnel and property security. CCTV surveillance systems and access control systems, patrol system and anti-theft alarm system, composed of security automation system to protect the security of the whole building.
2.4 satellite and cable TV system satellite and cable TV system is now generally set the base system.
Satellite receiving system is the use of satellites to direct forwarding TV signal system, its functions as a space Repeater, is to solve the problem of TV coverage rates and high quality transport TV image signal. Cable television (public antenna) system uses a set of high quality antenna to cable TV signal to distribute to all users of the TV system, that has a two-way communication, Videophone, telex transfer function, and can be used with the home computer terminal connected to the network.
2.5 underground garage management subsystem
Underground garage management subsystem on a computer network core, equipped with various modern car necessary equipment such as invoice/ticket machine, automatic fence machine, Induction coil, fees, etc., the system can be automatic or semi-automatic management two major action. Vehicle inductive loop detected a vehicle enters automatically start the invoice/ticket machine, if the user card and system are the same as the storage of messages, then start the fence machine open railings for vehicles entering the garage, and at the same time, the system automatically records the user card number and entry information. Vehicles appeared principle ibid. System management host can achieve the following functions--garage-case count and control, recording all operations and statistics, manage long-term users of the database.
2.6 public broadcasting and emergency broadcasting system
Public broadcasting mainly in the building market, business center, lobby, restaurant, public walks and other parts used for FM and am broadcasting programmes, dual-card playback signal, CD player and a microphone signal, the signal through the mixer can choose any of the above sources, all the way through the volume control to adjust the volume circuit to the appropriate level, then the region selector and output to the given regional broadcasting. When a fire alarm signal, the system will automatically close the public broadcast, automatically burning layer and its upper and down toggle to the emergency broadcast, when necessary, can also be manually to use machine with microphone carries on the artificial command. In addition to public broadcasting will switch to the emergency broadcast, building equipment, underground garage and other places set emergency radio speakers, usually does not work, only in fire at the fire emergency broadcast.
2.7 PABX system
Digital program-controlled telephone switching system provides sufficient road capacity assurance building all user requirements, and provide for future expansion left margin. The system can provide through simple configuration interface for ISDN functionality, and matching X.. 25 interface for packet-switched or matching other interface implementation features such as data communication through software settings, can be realized in this system, set up a private virtual network functionality. The system has a 1 to a dial-up, call specialBusiness, conference call, in case of busy callback, call privacy, e-mail, voice mail, and many other features, the system also has daily auto-detection, diagnosis, positioning and a host of serious failure to automatically switch to standby machine functions.
2.8 structured cabling system (PDS)
Structured cabling system is the entire building's "nervous system", speech communication, fax, and other image information, videoconferencing and video signal and data communications, and other networking applications. Structured cabling system consists of six separate subsystems that workspace subsystem, level subsystem, management subsystem, a vertical main subsystems, units between subsystems, complex subsystems. Workspace subsystem is the terminal device is connected to the information outlets of facilities including information outlets, the outlet boxes, connection cords, adapter, etc, are all kinds of data, voice line to the floor of each point. Level subsystem will link subsystem line extends to the user's workspace. Level system is arranged in the same floor, a termination in information outlets, the other a termination in floor distribution frame, mainly using unshielded twisted pair, need broadband transmission, you can use the "fiber to the desktop. Management subsystem is the main subsystems and level subsystem of bridges, while networking with floors provide conditions, including twisted pair jumper, jumper, when terminal equipment location or Bureau network structure change, sometimes just the way you can change the jumper, without rewiring. Vertical trunk subsystem is mainly used for the connection between the main building to the floor management, using large log-twisted pair or fiber-optic cable, connect the equipment on both sides, respectively, and the management of the jumper on the shelves. Device subsystem consists of equipment room in twisted-pair or fiber-optic cable, connect a jumper framework and related supporting hardware, lightning protection equipment, etc.
Complex subsystems to more building environment that is more than one building data communication signal connection integrated wiring system, using overhead installation or underground pipeline (or buried) in the laying of cables and cable as well as preventing surge voltage of electrical protection devices. Structured and integrated system combines voice signals, data signal and image signal wiring through unified specification and design, using the same transmission medium, information outlets, adapter, etc, the nature of the different signals to a standard set of cabling systems, performance for compatibility, openness, flexibility, reliability, advanced.

3. concluding remarks
Intelligent building weak electricity system is a product of the information age, combining computer technology, network technology, modern control technology, graphics display technology and communication technology, become intelligent building an extremely important part. With modern telecommunications, computer and network technology, intelligent building weak electricity system is integrated from facilities to system integration (illustrated), bringing the resources better, more complete, more focused and efficient management, thus realizing a truly intelligent.

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