Control method for preventing oil throwing during starting of multi-connected air conditioning unit

Abstract

The invention discloses a control method for preventing oil throwing during starting of a multi-connected air conditioning unit. The control method comprises specific steps as follows: a, the front end of an upper U-shaped pipe (1) is connected with an outlet of an oil separator (2); the rear end of the upper U-shaped pipe (1) is connected with the front end of a lower U-shaped pipe (3); the rear end of the lower U-shaped pipe (3) is connected with the lower end of a lengthened vertical pipe (4); the upper end of the lengthened vertical pipe (4) is connected with a first valve port of a four-way reversing valve (5); the bottom of the lower U-shaped pipe (3) and an inlet of a compressor (7) are communicated through an oil return pipeline (6) provided with an electromagnetic valve (8) and capillary pipes; b, the compressor (7) is started, and the electromagnetic valve (8) of the oil return pipeline (6) is opened after the compressor (7) operates for a period of time. According to the method, the operation cost is low, and the hidden danger of liquid impact on the compressor (7) is avoided.

Description

technical field [0001] The invention relates to a multi-connected air conditioner unit, in particular to a control method for avoiding oil throwing when the multi-connected unit is started. Background technique [0002] The multi-connected air conditioner unit in the prior art is referred to as a multi-connected unit for short, and it includes a plurality of outdoor units connected in parallel, a plurality of indoor units connected in parallel, and two refrigerant circulation main pipes connecting each indoor unit and outdoor unit. The multiple outdoor units connected in parallel communicate with the multiple indoor units connected in parallel through two main refrigerant circulation pipes. [0003] Each outdoor unit includes a compressor, an oil separator, a four-way reversing valve, an outdoor heat exchanger (a condenser for cooling and an evaporator for heating), a liquid receiver and a gas-liquid separator. The outlet of the compressor is connected with the inlet of the...

AI Technical Summary

Problems solved by technology

However, with the increasingly fierce competition in the market, various manufacturers have to compare pennies and pennies in order to save costs, and many manufacturers have omitted the liquid receiver. In this way, the amount of refrigerant stored in the oil separator has increased significantly, and the amount of oil thrown has become larger and larger. The hazards caused by the

[0009] In order to alleviate the situation of oil throwing when starting up, some people in the industry proposed to add a heating wire of about 30W to the oil separator to heat the refrigerant in the oil separator before the compressor starts to prevent it from mixing with lubricating oil after liquefaction, but the above The solution requires continuous consumption of electric energy, high operating costs, and when the room temperature is lower than -15°C, the heating effect is very poor, and it is difficult to vaporize the refrigerant in the oil separator; some people also propose to add an oil return pipe to the oil separator In this way, when starting up, the lubricating oil in the oil separator has an extra path to return to the compressor, but since the lubricating oil and liquid refrigerant in the oil separator are fully mixed, there is more lubricating oil returning to the compressor There will be a lot of liquid refrigerant, and there is a hidden danger of liquid hitting the compressor

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