Shanghai Jindi Yijing Community: ZTA damping electric butterfly valve in dry-type transformer room
Shanghai Dongfeng Pump Valve Factory provides ZTA damping electric butterfly valve products for the dry-type transformer room in Shanghai Jindi Yijing Community. This product is a damping butterfly valve electric butterfly valve product specially designed for transformers, which can reduce the noise of transformers by 85%. It is the exclusive product of transformer electric butterfly valves. Model: ZTA damping butterfly valve electric butterfly valve.
Introduction of transformer damping electric butterfly valve:
The damping electric butterfly valve in the machine room is designed according to the principle of "low frequency and large damping vibration isolator". The whole series uses multiple compression screw butterfly valve combinations in parallel to improve the stability of the product. Using metal wire mesh as damping material can not only increase the damping coefficient, but also extend the service life. In order to facilitate installation, the upper and lower end faces of the vibration isolator are sleeved with reference pads to increase the friction coefficient, which can be directly placed between the vibration isolation pedestal and the supporting structure, and generally do not need to be connected and fixed. When the vibration isolation equipment and the vibration isolator need to be connected and fixed, the upper end of the vibration isolator is equipped with a bolt device, that is, the "ZTA damping butterfly valve vibration isolator" can be used. When the vibration isolation equipment and the supporting structure need to be connected and fixed, the upper end of the vibration isolator is equipped with a bolt device, and the lower end is equipped with a fixed base plate, that is, the "ZTA type fixed damping butterfly valve vibration isolator" can be used. Therefore, ZTA damping butterfly valve vibration isolator has reasonable structure, convenient installation, low frequency, large damping, obvious vibration isolation and noise reduction effect. It is a universal pre compression damping butterfly valve vibration isolator. There are 20 specifications in the whole series of transformer damping electric butterfly valves, with a single vertical load ranging from 10kg to 5000kg, natural vibration frequency ranging from 2.16Hz to 4.79Hz, and damping ratio of 0.1. It is suitable for vibration isolation of mechanical equipment such as fans, water pumps, water chillers and air conditioning units, and vibration elimination and isolation of various precision instruments.
Sources of transformer noise:
There are three sources of transformer noise: iron core, winding and cooler, that is, the sum of noise caused by no-load, load and cooling system. The reason why the iron core produces noise is that under the action of the alternating magnetic field of the silicon steel sheet constituting the iron core, a small change, namely magnetostriction, will occur. The magnetostriction makes the iron core vibrate periodically with the change of the excitation frequency, which is caused by the magnetostriction deformation of the iron core and the electromagnetic force in the winding, oil tank and magnetic shield. The vibration of winding is caused by the electromagnetic force generated in the current winding, and the leakage magnetic field can also make the structural parts vibrate. The electromagnetic noise is caused by the longitudinal vibration of the core lamination induced by the magnetic field. The vibration amplitude is related to the magnetic flux density in the core lamination and the magnetic properties of the core material, but not to the load current. The electromagnetic force (and vibration amplitude) is proportional to the square of the current, and the emitted sound power is proportional to the square of the vibration amplitude. The noise of the transformer comes from the transformer body and the cooling system. The research results at home and abroad show that the noise caused by transformer body vibration is rooted in:
(1) Core vibration caused by magnetostriction of silicon steel sheet.
(2) There is electromagnetic attraction due to magnetic leakage between the silicon steel sheet joints and the laminations, which causes the vibration of the iron core.
(3) When the load current passes through the winding, the magnetic leakage generated by the load current causes the vibration of the coil and the oil tank wall. In recent years, due to the improvement of core stacking mode and the use of epoxy glass fiber adhesive tape for binding the core column and yoke, the core vibration caused by the electromagnetic attraction between the silicon steel sheet joint and the lamination is much smaller than that caused by the magnetostriction of silicon steel sheet, which can be ignored. The rated working magnetic density of the transformer is usually 1.5~1.8T. Research and tests at home and abroad have proved that within this magnetic density range, the vibration of the coil and box wall caused by the leakage porcelain generated by the load current is much smaller than the vibration of the iron core caused by the magnetostriction of silicon steel sheet, which can also be ignored. This means that the vibration of the transformer body is completely determined by the vibration of the iron core, and the vibration of the iron core can be regarded as completely caused by the magnetostriction of the silicon steel sheet. Another major source of transformer noise is the cooler. The fan will generate noise at the frequency of 500Hz to 2000Hz, and the human ear is certainly more sensitive to this broadband harmonic than the harmonic generated by the iron core at the basic frequency of IOOHz. The dominant frequency depends on many factors, including fan speed, number of blades and blade shape. The sound power level depends on the number of fans and the speed. Like the noise mechanism of the transformer body, the noise of the cooling device is also caused by their vibration. The root causes of the vibration are: (1) the vibration generated by the cooling fan and oil pump during operation. (2)
The vibration of the transformer body is transmitted to the cooling device through insulating oil, pipe valves and their assembly parts, which intensifies the vibration and noise of the cooling device. In addition, when the iron core is heated, its noise will increase with the increase of temperature due to the change of resonance frequency and mechanical stress. The environment of the operation site (such as the surrounding walls, buildings and installation foundations) also has an impact on the noise. For many strong wind cooling transformers, the cooler fan is a more obvious noise source than the transformer itself.
Introduction to transformer room:
Transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. Its main components are the primary coil, secondary coil and iron core (magnetic core). The main functions are: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. It can be divided into: power transformer and special transformer (furnace transformer, rectifier transformer, power frequency test transformer, voltage regulator, mine transformer, audio frequency transformer, intermediate frequency transformer, high-frequency transformer, impulse transformer, instrument transformer, electronic transformer, reactor, mutual inductor, etc.) according to the purpose. The circuit symbol usually uses T as the beginning of the number. For example, T01, T201, etc.
1. According to the number of phases: 1) Single phase transformer: used for single-phase load and three-phase transformer group. 2) Three phase transformer: used for voltage rise and fall of three-phase system.
2. According to cooling mode: 1) dry-type transformer: natural cooling or fan cooling by air convection, which is mostly used for small capacity transformers such as high-rise buildings, high-speed toll stations, local lighting and electronic circuits. 2) Oil immersed transformer: relying on oil as cooling medium, such as oil immersed self cooling, oil immersed air cooling, oil immersed water cooling, forced oil circulation, etc.
3. By purpose: 1) Power transformer: used for voltage rise and fall of power transmission and distribution system. 2) Instrument transformers: such as voltage transformers, current transformers, measuring instruments and relay protection devices. 3) Test transformer: it can generate high voltage and conduct high voltage test on electrical equipment. 4) Type of transformer: such as furnace transformer, rectifier transformer, regulating transformer, capacitive transformer, phase-shifting transformer, etc.
4. According to the winding form: 1) Double winding transformer: used to connect two voltage levels in the power system. 2) Three winding transformer: generally used in regional substations of power system to connect three voltage levels. 3) Autotransformer: used to connect power systems with different voltages. It can also be used as an ordinary step-up or step-down transformer.
5. According to the form of iron core: 1) Core transformer: used for high-voltage power transformer. 2) Amorphous alloy transformer: Amorphous alloy iron core transformer is a new type of magnetic conductive material, with no-load current reduced by about 80%. It is a distribution transformer with ideal energy saving effect, especially suitable for rural power grids and developing areas where the load rate is low. 3) Shell type transformer: special transformer for large current, such as furnace transformer and welding transformer; Or power transformers for electronic instruments, televisions, radios, etc.
Noise control measures for dry-type transformers:
Use ZTA type damping butterfly valve electric butterfly valve or ZTF type damping butterfly valve electric butterfly valve to reduce the noise generated by dry-type transformer. This product can reduce the noise of dry-type transformer by more than 75%. Shanghai Dongfeng Pump Valve Factory provides ZTA damping electric butterfly valve products for the dry-type transformer room in Shanghai Jindi Yijing Community. This product is a damping butterfly valve electric butterfly valve product specially designed for transformers, which can reduce the noise of transformers by 85%. It is the exclusive product of transformer electric butterfly valves. Model: ZTA damping butterfly valve electric butterfly valve.
Introduction to transformer noise:
Transformer noise is the sum of mechanical noise and air noise caused by irregular, intermittent, continuous or random noise generated by transformer body and cooling system in the process of body structure design, type selection layout, installation and use. The noise generated by transformers has a wide impact on residential areas, commercial centers, light stations, airports, factories and mines, enterprises, hospitals, schools and other places.
Hazards of transformer noise:
Noise does great harm to people. People who are under the influence of noise for a long time often have the following symptoms: First, it affects hearing. The degree of hearing loss is related to the time of human ear exposure in the noise environment, and the incidence of noise induced deafness in the noise environment above 85dB for a long time can reach 5%. The second is to affect learning and work and interfere with sleep Especially for students facing the pressure of study and examination, noise will affect their mental concentration. Every year when the college entrance examination and high school entrance examination are approaching, corresponding personnel will be arranged to deal with the noise problem, so that the noise will not affect the students' exam status. Third, it affects cardiovascular function and endocrine system. This is mainly manifested in tachycardia, arrhythmia, and high blood pressure. Fourth, it harms the central nervous system. People will suffer from headache, earache, dreaminess, memory loss, general fatigue and other symptoms when they are exposed to noise for a long time. Fifth, it affects children's intellectual development. It is reported that the intelligence of children in noise environment is 20% lower than that in quiet environment, and noise also has an impact on the growth of the fetus. Most transformer noises do not belong to high decibel strong noises, but the low-frequency noise generated in most cases will cause chronic damage to human body, It is easy to make people irritable, irritable, and sometimes even lose their sense. If disturbed for a long time, it may also cause nervous system diseases such as neurasthenia and insomnia. If pregnant women are exposed to low-frequency noise for a long time, it will also affect the development of the fetus in the abdomen. Experts from the Environmental Impact Assessment Office of the Chinese Center for Disease Control and Prevention pointed out that although low-frequency noise has less obvious impact on physiology than high-frequency noise, it can directly reach people's ear bones, make people's sympathetic nerves tense, and lead to tachycardia, high blood pressure, endocrine disorders and other symptoms. Because low-frequency noise is mainly transmitted through the structure, it is easy to cause people to feel resonance. Generally speaking, people's tolerance to low-frequency noise is relatively low. Under normal circumstances, 30 to 35 decibels is acceptable to ordinary people, and people above 35 decibels will obviously feel uneasy, irritable and other uncomfortable situations.
Shanghai Dongfeng Pump Valve Factory provides ZTA damping electric butterfly valve products for the dry-type transformer room in Shanghai Jindi Yijing Community. This product is a damping butterfly valve electric butterfly valve product specially designed for transformers, which can reduce the noise of transformers by 85%. It is the exclusive product of transformer electric butterfly valves. Model: ZTA damping butterfly valve electric butterfly valve.
Note: The static parameter diagram shows the bearing capacity/stroke curve of a group of isobars (0.2MPa~0.8MPa) and the volume/stroke curve at 0.7MPa.
The drawing shows the coordinate axis of bearing capacity, height and volume, as well as the shaded area on the right side of the design height line and safety extension line (electric butterfly valve shall not be used or used carefully in this area)