Multi-split system and oil return control method and device of multi-split system

Abstract

The invention discloses a multi-split system and an oil return control method and device of the multi-split system. The method comprises the following steps that in the operation process of the system, the minimum refrigerant flow needed for bringing lubricating oil in the system into an outdoor unit and the current refrigerant flow of the system are acquired every a first preset time; whether thecurrent refrigerant flow is smaller than or equal to the minimum refrigerant flow or not is judged; if the current refrigerant flow is smaller than or equal to the minimum refrigerant flow, the totaloil discharging amount of last time of an oil return compressor is acquired; whether the total oil discharging amount is larger than the maximum safe oil discharging amount or not is judged; and if the total oil discharging amount is larger than the maximum safe oil discharging amount, the system is controlled for oil return. Thus, it can be guaranteed that the situation that the compressor operates in an oil starvation manner due to the large oil discharging amount and small oil return amount is avoided, the capacity and energy efficiency of the multi-split system are effectively improved, and the method is simple and practicable.

Description

technical field [0001] The invention relates to the technical field of refrigeration, in particular to an oil return control method for a multi-line system, an oil return control device for a multi-line system, and a multi-line system. Background technique [0002] With the continuous increase of multi-connected air conditioner models (referred to as multi-connected), and its advantages of energy saving, intelligent adjustment, precise temperature control, high degree of automation, flexible use, and convenient management, it is widely used in large buildings and villas. Applications are increasingly widespread. Generally, due to the long pipeline of the multi-line unit, there are many positions where oil can be stored. With the increase of the system running time, more and more lubricating oil will be accumulated in the system pipeline. If the oil is not returned in time, the compressor Damage will occur due to lack of lubricating oil. [0003] In response to the above pr...

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Problems solved by technology

[0004] However, due to the inconsistent operating conditions of multiple units, the oil discharge volume is also inconsistent during operation. If the oil discharge volume is large and the oil return volume is small under operating conditions, the compressor may also run out of oil within a fixed period of time.

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