Ejection system, oil return system of water chilling unit, control method and water chilling unit

Abstract

The invention provides an ejection system, an oil return system of a water chilling unit, a control method and the water chilling unit, and relates to the technical field of oil return control. The ejection system comprises a first ejector, wherein the first ejector is provided with a first high-pressure inlet, a first mixing inlet and a first outlet, the first high-pressure inlet is used for introducing high-pressure gaseous refrigerant, and the first mixing inlet is used for introducing oil and liquid refrigerant mixed liquid; the first outlet is communicated with an oil tank through a firstbranch, and a first electromagnetic valve is arranged on the first branch; the first outlet is communicated with an air suction port of the compressor through a second branch, and a second electromagnetic valve is arranged on the second branch. When the guide vane opening degree is large and the impeller air suction capacity is high, the first electromagnetic valve is controlled to be opened to enable the first branch to be communicated, the second electromagnetic valve is controlled to be closed to enable the second branch to be disconnected, oil ejected by the first ejector directly entersthe oil tank and cannot be taken away by airflow at an air suction port of the compressor, and the oil shortage phenomenon of the oil tank is avoided.

Description

technical field [0001] The technical field of oil return control of the present invention, in particular, relates to an injection system, an oil return system of a chiller, a control method, and a chiller. Background technique [0002] Chillers (or air conditioning systems) are common refrigeration equipment that generally include centrifugal compressors. During the operation of the chiller, due to the high speed of the compressor and the large displacement, the resulting oil discharge is also large. Therefore, it is generally necessary to set up a special oil return path to recover the oil discharge from the compressor. [0003] In the prior art, the oil return is usually carried out through the primary injection and the secondary injection. The oil return of the primary injection is to lead the high-pressure gaseous refrigerant from the condenser into the ejector, and the mixed liquid containing lubricating oil and liquid refrigerant from the evaporator It is sucked out a...

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Problems solved by technology

[0005] In order to solve the technical problem in the prior art that the primary injection oil cannot remain in the suction port of the compressor, the main purpose of the present invention is to provide an injection system, an oil return system of a chiller, a control method, and a chiller

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