Steel structure development prospects

Steel structure development: should pay attention to three major areas

According to the development of the industry, Liu Jun believes that the development of three areas, such as offshore petroleum engineering equipment, steel structure housing and steel structure bridges, should attract the attention of the relevant national authorities. If it is valued and encouraged by the policy, it can fully achieve the goal of industrial doubling. .

Liu Jun pointed out that the output of offshore oil will reach 100 million tons in 2015. The goal of offshore engineering equipment enterprises is to provide a large amount of equipment for mining in the deep sea from 1,500 meters to 3,000 meters. The level and scale of the industry must be improved; Environmental protection, energy conservation and emission reduction and circular economy policies, its industrialized and standardized steel structure residential products have broad and unlimited market space; at present, there are less than 1% of the 590,000 highway bridges in China, and the railway system develops at a high speed. With the bridge road, 80% are prestressed reinforced concrete bridges. The steel structure bridges accounted for 41% in Japan and the United States accounted for 33%. This shows that the market demand and industrial development of China's steel structure bridges are still far from the developed countries.

China's steel structure industry has developed rapidly in the past 10 years, and has become the largest steel structure country with the largest steel structure consumption, the strongest manufacturing and construction capacity, the industry scale and the enterprise scale.

Steel structure enterprises: we must pay attention to the development of the "12th Five-Year Plan"

Liu Jun pointed out that the successful construction of major steel structure projects in various places shows that China's comprehensive technical level of steel structure has reached the international advanced level. However, China's steel structure industry still has a big gap compared with developed countries in terms of informationization, automation, standardization and scientific research and innovation. 2011 is the year of the national “Twelfth Five-Year Plan”. Relevant national ministries, industry associations, enterprise groups and steel structure enterprises are conducting research, analyzing the market and future development trends. The National Development and Reform Commission, the Ministry of Industry and Information Technology, and the Ministry of Science and Technology are also studying the strategic new industry identification and planning goals. For industries with international advanced level, strong independent innovation capability, strong international competitiveness, and the ability to occupy more markets, they will be included in the plan and given Support and support policies. Opportunities are also challenges. Whether China's steel structure industry can go up the scale and scale, the development during the 12th Five-Year Plan period is crucial.

Liu Jun said that after investigation and research, the China Steel Structure Association drafted the "Strategic Thoughts and Suggestions on the Steel Structure Industry in the National Twelfth Five-Year Plan" after listening to relevant experts' opinions and suggestions, inviting relevant personnel. After the opinions, the association will organize relevant experts to implement and improve them in order to promote greater development of the steel structure industry during the “12th Five-Year Plan” period.

Low Voltage Switchgear or LV Switchgear
Generally Electrical Switchgear rated upto 1KV is termed as low voltage switchgear. The term LV Switchgear includes low voltage circuit breakers, switches, off load electrical isolators, HRC fuses, earth leakage circuit breaker, miniature circuit breakers (MCB) and molded case circuit breakers (MCCB) etc i.e. all the accessories required to protect the LV system.
The most common use of LV switchgear is in LV distribution board. This system has the following parts
Incomer
The incomer feeds incoming electrical power to the incomer bus. The switchgear used in the incomer should have a main switching device.
 The switchgear devices attached with incomer should be capable of withstanding abnormal current for a short specific duration in order to allow downstream devices to operate. But it should be cable of interrupting maximum value of the fault current generated in the system. It must have interlocking arrangement with downstream devices. Generally air circuit breakers are preferably used as interrupting device. Low voltage air circuit breaker is preferable for this purpose because of the following features 1.Simplicity
2.Efficient performance
3.High normal current rating up to 600 A
4.High fault withstanding capacity upto 63 kA
Although air circuit breakers have long tripping time, big size, high cost but still they are most suitable for low voltage switchgear for the above mentioned features. 
Sub - Incomer
Next downstream part of the LV Distribution board is sub - incomer. These sub - incomers draw power from main incomer bus and feed this power to feeder bus. The devices installed as parts of a sub - incomer should have the following features 1.Ability to achieve economy without sacrificing protection and safety
2.Need for relatively less number of inter - locking since it cover limited are of network.


ACBs (Air Circuit Breakers) and switch fuse units are generally used as sub - incomers along with molted case circuit breakers (MCCB). 

Feeders
Different feeders are connected to the feeder bus to feeds different loads like, motor loads, lighting loads, industrial machinery loads, air conditioner loads, transformer cooling system loads etc. All feeders are primarily protected by switch fuse unit and in addition to that, depending upon the types of load connected to the feeders, the different switchgear devices are chosen for different feeders. Let's discuss in details •Motor Feeder
•Motor feeder should be protected against over load, short circuit, over current up to locked rotor condition and single phasing.
•Industrial Machinery Load Feeder
•Feeder connected industrial machinery load like oven, electroplating bath etc are commonly protected by MCCBl and switch fuse disconnector units
•Lighting Load Feeder
•This is protected similar to industrial machinery load but additional earth leakage current protection is provided in this case to reduce any damage to life and property that could be caused by harmful leakages of current and fire.
In LV switchgear system, electrical appliances are protected against short circuit and over load conditions by electrical fuses or electrical circuit breaker. However, the human operator is not adequately protected against the faults occurs inside the appliances. The problem can be overcome by using earth leakage circuit breaker. This operates on low leakage current. The earth leakage circuit breaker can detect leakage current as low as 100 mA and is capable of disconnecting the appliance in less than 100 msec. 

LV Switchgear

LV Switchgear,Low Voltage Switchgear,Metal LV Switchgear

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