As we all know, high-rise buildings in the event of a fire, often based on the bolt system or sprinkler system to build a high-rise self-help. In other words, high-rise buildings are mainly built on their own are crucial, here on fire pump safety fire facilities to complete the fire fighting. For this reason we talk about fire pump start-up today. First, we should come to understand that fire water supply equipment is composed of fire pump, pipe, valve, electric control cabinet and a meter. The factors affecting the reliability of fire water supply equipment are many, from the mathematical point of view to analyze the probability to come to conclusions of reliability is a commonly used method, this article only from the start of the fire pump with the application of related new technologies To discuss the reliability of water supply equipment. Second, the commonly used fire pump start-up method and reliability analysis 1, direct start-up method Direct start-up method using the least number of lines, are passive components, this start-up mode to fire pump start the most rapid, and the maximum starting current of the grid transformer capacity The requirement is also the largest, taking into account the start-up characteristics of the current use of the pump motor is good, but also because the pump is the square of the load, but also can be considered as light-load start, low-voltage motors can consider a single Motor Power up to 90kW, The motor (6kV or 10kV) has a power range of up to several megawatts. When the fire pump overload, over-current situation, the type of thermal magnetic trip is protected, but its thermal relay in action, "only alarm, do not switch off." This is the easiest, most economical and reliable way to start. 2, Star-corner start-up method Star-corner start-up method is slightly more complicated than the direct start-up method, and both are passive devices. The start-up time is usually completed within 60s, and the starting current is smaller than the direct start-up mode. Therefore, consider a single motor power can be set to 110kW, and this line is only used for low-voltage motors. When the fire pump overload, over-current situation, the type of thermal magnetic trip is protected, but its thermal relay in action, "only alarm, do not switch off." As the line is a little more complicated, the probability of failure is higher than the former. 3, since the lotus root transformer start-up method since the lotus root transformer start-up line is more complex than the first two, are also passive devices, the general start-up time can be completed within 90s, the starting current is also smaller than the previous two, so this single Taiwan motor power range up to 160kW, this line is only used for low voltage motor. When a fire pump overload or overcurrent condition occurs, the thermal relay is protected by the type of thermal relay. However, when its thermal relay is in operation, it "alarms only and does not open." Because the line is also more complicated than the former two, fault The probability is higher than the first two. 4, KB0 start mode KB0 start mode is passive start mode, it is the main function of circuit breakers, contactors, overload relays, isolating switches and other discrete components integrated and can integrate a variety of signals to achieve control and protection features Self-contained within the product. With small size, high performance indicators of short-circuit breaking, long mechanical and electrical reliability and high reliability, the use of safe and convenient, energy-saving materials and so on. However, this device is limited to low-voltage, low-pressure fire pumps due to its rated current rating of 125A and high voltage products. In addition, be aware that in the selection, be sure to use fire-type products. Because when the fire pump overload, over-current, the device "does not switch off, only the alarm," in line with fire pump control and protection requirements. This method applied to low-power fire pump case, the obvious improvement of reliability, better than the previous methods, at the same time, the cost will be higher than that. 5, soft-start method RQ device is the soft starter. This is an active start mode, the line is more complex than the previous few. The biggest advantage of this method is no start-up current, the start-up time can be conveniently set according to the pump motor power in 0 ~ 3600s, so the power range of a single motor can reach several hundred kilowatts. For the reason of the device, Motor (there are already reports on the application of high-pressure pump), but also to adapt to the situation of EPS power supply. Because of its electronic protection, fire pump overload, overcurrent, undervoltage, lack of power and other reasons will make it immediately into the "gate" protection, turn off the output, which is the characteristics of active devices. In the event of a fire, once the fire pump overload or power overvoltage, undervoltage, etc., fire pump will immediately stop running. So its reliability is slightly worse than the previous methods. 6, inverter start-up mode When used in high-pressure pump, the need to configure the appropriate input and output transformers. This is an active start mode, the way the line and soft starter complexity even more. There is no start-up current, the start-up time can be arbitrarily and conveniently set, single motor power and motor voltage range up to several megawatts and 10kV. EPS power supply is also very suitable for the situation. Because of its complicated circuit, especially the active inverter, so its reliability is worse than the previous few. In summary, the soft starter and inverter are active start mode, the other way is passive mode. So how to evaluate the reliability of the active way? Let us first look at the current situation of fire pump applications: soft starter and inverter are imported products, since the mid-1980s in China began widespread use. However, we noticed a phenomenon that was not covered in the NFPA standard and FM certified products, and the use of soft starters and frequency converters as start-up methods and articles for fire pumps. This can not be seen as their negligence. Because, in many countries in Europe and the United States imports of equipment, production and use of life in the pump widely used soft starter and inverter. This can be understood as the way they are based on the reliability of fire-fighting equipment and are not advocated. However, the situation in our country is quite different. The active start-up mode has been widely adopted in the start-up of fire pumps. At present, the quality of soft starters and frequency inverters used in our country varies greatly, and the quality of the brands is also uneven. The level of the users is even worse and worse. There is a big difference in understanding and understanding between the designers and the applicators. Such as: fire pump overload protection, the active and passive way is completely different. When in passive mode, its thermal magnetic protection (thermal relay) after overload, only alarm pump does not stop. However, in active mode, its accurate electronic protection immediately shuts down the output of the soft starter or inverter and stops pumping after an overload. At this point, if a fire event occurs, fire pump is activated to give the source of water, thus completing Fire extinguishing it? I believe that the choice of fire pump start-up mode should not be used on the active mode, passive mode should be used. Direct start mode to meet most of the buildings of fire water equipment capacity requirements, it should be the first recommendation. At the moment, it is time to standardize the way fire pumps are started (at present, there is not a single standard in our country that addresses this issue), otherwise it is undoubtedly a management loophole that emphasizes the importance of fire safety today Building fire safety instability. Finally, let's talk about what to do if the fire pump does not start up when there is a fire pump start-up control circuit (secondary circuit) in the event of a fire? Here's a fire-fighting water supply control device with an emergency start fire pump mechanism . The utility model is characterized in that the utility model comprises the structure of the connection structure of the main circuit composed of the dual power conversion circuit and the low voltage electrical appliance and the voltmeter, the ammeter, the several indicator lights and the button on the front panel of the cabinet; the utility model comprises an operating handle and a bayonet pin Operating lever driven linkage rod, linkage rod on the reset spring, linked by the lever-driven rotary switch, driven by the linkage rod and the bar by the rod-driven adjustable short rod in the fire emergency Under the start of fire pump manual mechanical device. Rotary switch driven by the linkage lever, the operating handle is rotated 90 ° counterclockwise after the electrical state is off. The short rod is made of insulating material and has a screw thread and two nuts for adjusting and fastening the short rod. The standard for adjusting the short rod is to make it away from the main contactor in the main circuit by the handle The driving force at the time of pushing may make all the contacts of the main contactor solidly connected but can not produce the virtual connection. The bayonet pin is installed on the side beam of the cabinet body and is the movable shaft of the interlocking rod. After the handle is rotated by 90 ° counterclockwise and pressed, the bayonet catch is to be stuck by the interlocking rod so that the interlocked short rod can be sustained Compression on the main contactor. Then, when the handle is rotated clockwise, the return spring on the linkage returns it to its position. The beam is an I-beam structure, one end of which is fixed in the form of a shaft on the other side of the beam of the cabinet, so that the axis can be moved in parallel; the other end is moved parallelly by the linkage rod, This parallel movement drives the short rod to act to compress or apply the main contactor. When a fire incident occurs, if the fire pump control cabinet circuit fails so that the fire pump can not be activated, the authorized person may operate the handle immediately and rotate it counterclockwise by 90 ° and press it properly. At this point the main circuit of the main contactor is forced down, that is connected to the fire pump motor feed power, so that the pump was forced to start (rather than the original circuit according to the row of the start-up process). The reason why the counterclockwise rotation must be done first is to operate the rotary switch to disconnect the power of the secondary control circuit in the control cabinet first. After the fire event is over, the authorized person simply rotates the handle clockwise and it is automatically reset by the return spring to its original state. At present, the technology has been successfully used in a number of large fire fighting water supply equipment in public buildings. Such as: Beijing Oracle headquarters (one of the world's top 500), China BlueStar Group headquarters building, the People's Theater and a military project. This start-up technology has become a new technological breakthrough in the way of start-up of fire-fighting water supply, and is welcomed by users and fire control departments for its creativity, novelty and practicability. (Editor: Xiaoxia QQ:) Recommended reading: 2017 exhibition information
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