VRF (varied refrigerant volume) air conditioning system and control method of VRF air conditioning system

Abstract

The invention relates to a VRF (varied refrigerant volume) air conditioning system, which comprises a compressor, an evaporator, a condenser, an outdoor environment temperature sensor and an electronic expansion valve opening degree control device, wherein the electronic expansion valve opening degree control device comprises a controller, temperature sensors, a pressure sensor and an electronic expansion valve, the temperature sensors, the pressure sensor and the electronic expansion valve are respectively in electric signal connection with the controller, the temperature sensors are respectively arranged on an exhaust pipe of each compressor for detecting the exhaust temperature value, the pressure sensor is arranged on a main exhaust pipe of a plurality of compressors for detecting the total exhaust pressure, and the electronic expansion valve is arranged at the back end of the condenser for realizing the throttling on an outdoor unit. The invention also discloses a control method of the VRF air conditioning system. The control method avoids the defects that in the practical use, when the exhaust temperature is too low, excessive coolants are deposited at the air return side of the system, the compression with liquid of the compressor is caused, when the exhaust temperature is too high, the compressor is overheated, and the lubricating oil carbonization of the system is caused. The stable and efficiency operation of the whole system is guaranteed.

Description

technical field [0001] The invention relates to a multi-connected air-conditioning system and a control method thereof, belonging to the technical field of air-conditioning. Background technique [0002] Multi-connected air conditioner (heat pump) units are referred to as multi-connected units. They were born in Japan in the 1980s and began to develop in China at the beginning of this century. Multi-split is a new type of central air-conditioning system that is different from ordinary air-conditioning systems. Its core is to achieve the capacity requirements of different rooms by adjusting the frequency and output ratio of the compressor. Compared with traditional central air-conditioning, it is energy-saving, comfortable, and Control flexible features, and easier to install and maintain. At present, electronic expansion valves have been widely used as throttling parts of multi-connected external units because of their precise control of refrigerant flow and reasonable cost...

AI Technical Summary

Problems solved by technology

Its ultimate purpose is to control the electronic expansion valve by the superheat of the return air, and in the low temperature environment, the measured value of the temperature sensor will have a large deviation, which will cause deviations in its control logic, which limits the exhaust temperature to less than 55 Within a certain constant between -65, under different actual combinations and operating conditions, the opening of the electronic expansion valve is too large, which means that the exhaust temperature is too low, which will cause too much refrigerant to migrate back to the external unit and cause The compressor is compressed with liquid, which affects the stable operation of the system and causes great damage to the compressor

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