Control method and device for magnetic levitation chiller main engine of office building central air-conditioning system

Abstract

The invention relates to a control method of magnetic suspension cold water host machines of an office building central air conditioning system. The control method comprises the following steps: (S11) a performance curve of a magnetic suspension cold water host machine set and a performance curve of single freezing pump are obtained; (S12) the performance curve of the magnetic suspension cold water host machine set and the performance curve of the single freezing pump are fitted by applying a least square method to obtain a mathematical model of the magnetic suspension cold water host machine set and a mathematical model of the single freezing pump; (S13) based on the energy consumption added by change of the obtained single freezing pump to two freezing pumps, the mathematical model of the magnetic suspension cold water host machine set and the mathematical model of the single freezing pump are combined to obtain a corresponding relation curve between total energy consumption and part load of the central air conditioning system; (S14) the integration is performed according to the corresponding relation curve between total energy consumption and part load of the central air conditioning system to obtain a preset part load range of the central air conditioning system; and (S15) the opening number of the magnetic suspension cold water host machines of the central air conditioning system is controlled according to the preset part load range of the central air conditioning system.

Description

technical field [0001] The invention relates to the field of central air-conditioning in office buildings, and more specifically, relates to a method and device for controlling a magnetic levitation chiller host of an office building central air-conditioning system. Background technique [0002] The method of adding and subtracting machines used in the traditional office building central air-conditioning chiller unit is to compare the set operating points, and perform adding and subtracting operations according to the size relationship between the current operating conditions and the set operating points. For example: when the cooling load of the central air conditioner reaches 100% of the load of a single host and runs for more than 5 minutes, perform additional machine operation and turn on another chiller to meet the current cooling load demand; when the cooling load of the central air conditioner is less than two chillers When the total load of the unit is 30% and runs f...

AI Technical Summary

Problems solved by technology

If the host is under full load or overload for a long time, it will greatly reduce the service life of the host and increase the failure rate of the host; simple comparison of the set point will easily cause vibration around the set point, that is, frequent start and stop, addition and subtraction of the machine , in the context of advocating system life cycle control today, these shortcomings are obviously fatal

[0004] On the other hand, with the continuous innovation of the main unit structure of the central air conditioner, the magnetic levitation chiller impacts the traditional screw and centrifugal chiller market. There is a huge difference in the operating curve of the screw machine and the centrifuge, and the problem of poor compatibility between the traditional central air-conditioning control strategy and the magnetic levitation chiller has also appeared.

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