Frequency conversion control system and method for constant temperature and humidity device

Abstract

The invention discloses a frequency conversion control system and method for a constant temperature and humidity device. The frequency conversion control system comprises a temperature sensor, a PID controller, a D / A conversion unit and a frequency converter. The temperature sensor is used for measuring the actual condensing temperature of a condenser. The PID controller is used for calculating the frequency value of the frequency converter, needing to be executed, through a PID calculation method according to the difference between the measured actual condensing temperature and the set ideal condensing temperature. The D / A conversion unit is used for converting the frequency value, obtained through the calculation of the PID controller, of the frequency converter into an analog signal capable of being recognized by the frequency converter. The frequency converter is used for regulating the rotational speed of a fan according to the corresponding analog signal to control the condensing temperature of the condenser in a real-time manner to enable the condenser to reach the ideal condensing temperature and the condensing pressure to be higher than the evaporation pressure limit. The frequency conversion control system is reasonable in design, and perennial stable operation of the constant temperature and humidity device can be realized.

Description

technical field [0001] The present invention relates to the technical field of constant temperature and humidity equipment, and more specifically relates to a frequency conversion control system and method for an outdoor unit of constant temperature and humidity equipment. Background technique [0002] The existing constant temperature and humidity equipment generally relies on freezing and dehumidification in consideration of its economy and stability. When the constant temperature and humidity equipment is running at low temperature, the surface temperature of the evaporator must be lower, but the temperature will be lower than 0°C for a long time, which will cause evaporation. The evaporator is frosted, and defrosting will cause temperature and humidity fluctuations, so long-term operation and need to be used as low-temperature and low-humidity constant temperature and humidity equipment must limit the evaporator temperature to not be too much lower than 0°C, and the evapo...

AI Technical Summary

Problems solved by technology

When the ambient temperature of the condenser is too low (below -10°C in winter in the north), and the condensation temperature is lower than the limited evaporation temperature of the evaporator, that is, when the condensation pressure is lower than the evaporation limit pressure, the refrigerant cannot complete the refrigeration cycle. Refrigeration and dehumidification effect, the equipment can not operate normally, so the year-round operation of the equipment cannot be realized

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