Hezhou customized Boiler centrifugal fan Fan performance parameters. The performance parameters of fan mainly include flow, pressure, power, efficiency and speed. In addition, the size of noise and vibration is also the main fan design index. Flow, also known as air volume, is expressed by the volume of gas flowing through the fan in unit time; Pressure, also known as wind pressure, refers to the pressure rise value of gas in the fan, including static pressure, dynamic pressure and total pressure; Power refers to the input power of the fan, namely shaft power. The ratio of effective power of fan to shaft power is called efficiency. Boiler centrifugal fan company The total pressure efficiency of fan can reach 90%. Fans are widely used for ventilation, dust discharge and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; Ventilation and induced draft of boiler and industrial furnace; Cooling and ventilation in air conditioning equipment and household appliances; Drying and selection of grain; Wind source of wind tunnel and inflation and propulsion of hovercraft. The working principle of the fan is basically the same as that of the turbine compressor, but because the gas flow rate is low and the pressure changes little, it is generally unnecessary to consider the change of gas specific volume, that is, treat the gas as an incompressible fluid

Hezhou customized Boiler centrifugal fan Forecasts from foreign markets. The member units of China General Machinery Fan Industry Association exported 7969 fans in 2000, with the export delivery value of 81.157 million yuan. From 1991 to 2000, the total number of exported fans was 72876, and the total value of export delivery was 747.26 million yuan. Boiler centrifugal fan company The trend of global economic integration is becoming more and more obvious. The economies of all countries will further depend on each other. International economic cooperation and exchanges will become closer and closer. The international market is at a stage of significant intersection and integration. At the same time, the pace of global industrial restructuring is accelerating, and significant progress has been made in the scale and depth of international division of labor. Developed countries continue to shift industrial production to capital intensive and technology intensive industries, and labor-intensive products are transferred to developing countries and regions. This provides a good development opportunity for China to play its own advantages and enter the international market. Since the 1970s, China has introduced foreign advanced technology of centrifugal compressor, which has improved the product grade through digestion, absorption and innovation. As long as the quality and delivery time are guaranteed and the price advantage is used, it is competitive internationally. Especially after China's entry into WTO, it is entirely possible to increase the fan export. From the historical analysis, the main export varieties are small and medium-sized fans and fan accessories. The main gap between domestic enterprises producing such fans is that the surface quality cannot meet the export requirements. If the appearance quality is improved and the price is favorable, the prospect in the foreign market is broad. From 1991 to 2000, the fan exports of small and medium-sized fans were not stable enough, and there was no obvious growth trend. However, with the continuous progress of technology, it is expected that the export volume of such fans will continue to increase, and it is predicted that the annual average growth rate will be about 5% on the basis of 2000. customized Boiler centrifugal fan The export of centrifugal compressors and blowers increased significantly from 1991 to 2000, reaching 870000 sets in 2000. The main exporting countries are India, Pakistan, Iran, Vietnam and other developing countries. It is expected that this trend will continue to develop, reaching 1 million units per year.

9. Since the flow, total pressure, main shaft speed and shaft power of the fan have a fixed relationship, the main shaft speed should not be changed when the motor capacity does not change. If the main shaft speed increases, the motor may be burned due to overload. The motor power used by the fan refers to the power not required when the air inlet and outlet are fully open in terms of mechanical losses and due reserves under a specific mine. If the outlet or inlet of the fan is not connected to the pipeline or is idle without external resistance, the motor may also be burned out. For safety, a valve shall be added to the outlet or inlet pipeline of the fan, and it shall be closed when starting the motor. After turning, the valve shall be slowly opened until the specified working condition is reached, and attention shall be paid to whether the current of the motor exceeds the specified value. High power motors must be started in proper ways, such as voltage reduction, frequency conversion, etc.

Gas compression and gas transmission machinery is a machine that converts rotating mechanical energy into gas pressure energy and kinetic energy and transports gas. The main structural components of the fan are impeller, casing, air inlet, support, motor, pulley, coupling, silencer, transmission parts (bearings), etc. customized Boiler centrifugal fan The unpowered fan uses the air thermal convection caused by the natural wind force and the indoor and outdoor temperature difference to drive the turbine to rotate, thus using the centrifugal force and negative pressure effect to exhaust the indoor stale hot air. Hezhou Boiler centrifugal fan company The fan is related to the transmission and distribution energy consumption of the system, and is a very critical part of building energy conservation. According to the fan inspection conducted by the National Air Conditioning Equipment Quality Supervision and Inspection Center for many years, many fans have problems under rated conditions, so it is necessary to produce and manufacture fans in strict accordance with product standards. customized Boiler centrifugal fan At the beginning of the fan operation, the vibration of the bearing is very small, but with the extension of the operating time, the dust in the fan will be unevenly attached to the impeller, gradually destroying the dynamic balance of the fan, making the bearing vibration gradually increase. Once the vibration reaches the maximum allowable value of 11mm/s of the fan (the maximum allowable value expressed by the amplitude value is as follows), The fan must be shut down for repair (dust accumulation shall be removed and dynamic balance shall be redone). Because it is very dangerous at this time, users must not use it forcibly. When the fan vibration is close to the dangerous value, the vibration measuring instrument will give an alarm.

Selection and application of fan performance (I) Description of fan performance: 1. № 10, 12, 16, 20 are converted according to dimensionless performance of № 10 model. 2. № 5, 6, 8 are converted according to dimensionless performance of № 5 model. 3. № 5 and below shall be determined according to the performance of the measured prototype. Note: According to the dimensionless performance curve conversion formula, total pressure H=ρ u2 H (Pa) flow Q=900 π D22 uQ (m3/h) shaft power N=N × D22u3 ρ/4000 (kw), where D2 - impeller outer diameter (m) u - impeller outer edge linear speed (m/s) ρ - gas density (Kg/m3), the required power rate shall be based on shaft power plus mechanical loss and motor reserve. 4. The solid line is № 5 model, and the dotted line is № 10 model. The performance of the fan is expressed by the flow, total pressure, main shaft speed, shaft power, efficiency and other parameters of the fan, and there are certain relationships between the parameters, which are listed in the following table. The relationship of fan performance parameters changes density ρ, speed n changes speed n, atmospheric pressure P, gas temperature t Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 ρ 1/ρ 2 N1/N2=(n1/n2) 3 ρ 1/ρ 2 η 1=η 2 Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 (P1/P2) (273+t2/273+t1) N1/N2=(n1/n2) 3 (P1/P2) (273+t2/273+t1) η 1=η 2 Note: 1. In the middle, Q represents flow (m3/h), H represents total pressure (Pa), N Represents shaft power (kw), η represents total pressure efficiency, ρ represents density (kg/m3), t represents temperature (℃), n represents speed (r/min), and P represents atmospheric pressure (Pa). 2. The footnote symbol 2 indicates the known performance and related parameters, and the footnote symbol 1 indicates the required performance and related parameters. （