Air conditioner system and economizer electronic expansion valve control method

Abstract

The invention discloses an air conditioner system and an economizer electronic expansion valve control method. The air conditioner comprises a compressor, an outdoor heat exchanger, a use-side heat exchanger, an economizer, a four-way valve, an economizer electronic expansion valve, a control unit, a use-side discharge water temperature sensor, an outdoor temperature sensor, an economizer electronic expansion valve downstream temperature sensor and a compressor rotation speed sensor, wherein the use-side discharge water temperature sensor, the outdoor temperature sensor, the economizer electronic expansion valve downstream temperature sensor and the compressor rotation speed sensor are connected with the control unit. The air conditioner system has the advantages that by collecting use-side discharge water temperature, outdoor temperature, economizer electronic expansion valve downstream temperature and compressor rotation speed and using a two-dimensional fuzzy controller to control the opening degree of the economizer electronic expansion valve, and the system gets rid of the dependence of the prior art on superheat degree; the system does not depend on the superheat degree, control stability of the economizer electronic expansion valve is achieved, low-temperature heating ability can be increased effectively, energy efficiency ratio can be increased evidently, and the system's adaptability to various working conditions is increased.

Description

technical field [0001] The invention belongs to the technical field of low-temperature heat pumps, and in particular relates to an air-conditioning system and an economizer electronic expansion valve control method. Background technique [0002] Low ambient temperature heat pump (chilled water) units have been used more and more in the north. The nominal working condition is -12°C outside ambient temperature, the minimum working condition requires the operation at -25°C outside ambient temperature, and the low temperature working condition is outside ambient temperature -20°C. Low ambient temperature causes a drastic attenuation of the heating capacity and energy efficiency of the system. In order to improve the heating capacity and energy efficiency at low temperature, the air conditioning system mostly adopts steam-injection enthalpy compressors. The principle is that in front of the economizer, the refrigerant is divided into A and B paths, of which A path is throttled a...

AI Technical Summary

Problems solved by technology

For the control of the electronic expansion valve, most of the existing technologies use superheat and exhaust superheat to carry out PID control. If the economizer also uses superheat or exhaust superheat as the control target, it will easily lead to Coupling with the economizer expansion valve produces shock superposition, which makes the control of the expansion valve difficult to stabilize, and the PID parameters are poorly adaptable to multiple working conditions

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