Variable-frequency air-cooled water chilling unit and variable-working-condition starting control method thereof

Abstract

The invention discloses a variable-frequency air-cooled screw water chilling unit and a variable-working-condition starting control method thereof. The variable working condition starting control method comprises the following steps that the initial frequency of a variable frequency fan and the initial frequency of a variable frequency compressor are controlled according to the interval where theenvironment temperature detected during starting is located; after the compressor is started for v seconds, the frequency of the variable frequency fan is adjusted according to the comparison result of the difference value of the high-pressure pressure and the low-pressure pressure and the first preset pressure and the comparison result of the low-pressure pressure and the second preset pressure;and after the compressor is started for n seconds, the frequency of the variable frequency compressor is adjusted according to the comparison result of the high-pressure pressure and the variable frequency fan closing pressure. The unit is provided with a high-low pressure sensor and an environment temperature sensor to adjust the frequency of the compressor or the frequency of the fan, and the purpose of optimizing the starting reliability of the compressor under different working conditions is achieved.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a frequency-variable air-cooled screw chiller and a start-up control method thereof under variable working conditions. Background technique [0002] The frequency conversion air-cooled screw chiller is generally installed in the outdoor environment. Due to the influence of the ambient temperature, chilled water temperature, and usage habits in the project, the compressor starts and operates under complex and changeable conditions, and the ambient temperature and chilled water temperature are high or A lower value will have an adverse effect on the reliability of the compressor operation, mainly in the following two aspects: [0003] 1. In a low temperature environment, the chilled water temperature of the unit and the ambient temperature are relatively low. At this time, the pressure difference in the operating condition of the compressor is small. Larger, but this kind...

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Problems solved by technology

[0006] This invention proposes a variable frequency air-cooled chiller and its variable working condition start-up control method to solve the problem of starting up the variable frequency air-cooled screw chiller at different ambient temperatures reliability

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