A flow self-adaptive control method for a range hood

Abstract

An adaptive control method for the flow of range hoods, including range hoods installed on different floors, the air outlets of each range hood are connected to the common flue through their own smoke pipes, the self-adaptive control method adopts a single machine Mode, first use the speed to judge the current working state of the range hood (the speed change is small in the state of high resistance, but the power change is obvious), if it is high resistance, use the power-flow relationship to calculate, if it is low speed and low resistance, use the current Gear speed detection or counter electromotive force to calculate the speed, and then use the one-to-one correspondence between the speed and flow in the same gear to calculate the current actual flow, calculate the difference from the target flow, choose to adjust one or more gears, and calculate whether it can Control to flow range. Compared with the prior art, the flow adaptive control method has a simple control method and higher control precision. And the stand-alone mode setting time pre-determines peak or non-peak hours, which can reduce the number of adjustments.

Description

technical field [0001] The invention relates to a flow adaptive control method, in particular to a range hood flow adaptive control method. Background technique [0002] At present, the floors of newly-built buildings in cities are generally higher and higher. Since the outlets of high-rise public flues are generally set on the top of the floors, the switching status of the range hoods of each user's home will affect the resistance of the system outlet, making the smoke exhaust situation of users at the bottom poor. . In recent years, the user-side adjustable angle valve combined with the roof flue outlet main fan centralized filtration and discharge has been applied in some well-decorated buildings in recent years. The roof main fan performs frequency conversion + valve preset angle to achieve flow for users with different operating rates. Allocation, although this method can solve the poor smoke exhaust situation of bottom users to a certain extent, and effectively contro...

AI Technical Summary

Problems solved by technology

[0002] At present, the floors of newly-built buildings in cities are generally higher and higher. Since the outlets of high-rise public flues are generally set on the top of the floors, the switching status of the range hoods of each user's home will affect the resistance of the system outlet, making the smoke exhaust situation of users at the bottom poor.

In recent years, the user-side adjustable angle valve combined with the roof flue outlet main fan centralized filtration and discharge has been applied in some well-decorated buildings in recent years. The roof main fan performs frequency conversion + valve preset angle to achieve flow for users with different operating rates. Allocation, although this method can solve the poor smoke exhaust situation of bottom users to a certain extent, and effectively control the flow rate and noise of the entire flue system, but it needs to be adjusted and adapted according to the flue of different buildings, and the same set of programs cannot be self-adaptive For many buildings, the amount of calculation before installation is particularly large, and the test of the flow rate sensor or pressure sensor fluctuates greatly under high resistance and low flow conditions, and the data cannot be directly used for judgment

[0003] According to the test, according to the CFD analysis and comparison of the open state of the valve plate, it can be seen that the velocity distribution of the flow field before and after the valve plate is extremely uneven under the state of small angle and high resistance. If only a single-point measurement or a few The flow rate obtained by point measurement and then the average value multiplied by the correction coefficient cannot accurately represent the actual flow rate

In addition, due to the low flow rate of the range hood in the state of high resistance, the torque load of the motor does not change much, resulting in a small change in the speed. In this range, only the speed-flow function relationship is used to fit the judgment inaccurately, which will easily lead to back and forth adjustments, and the user feels the air volume. And the sound fluctuates, affecting the user experience

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