Oil returning device and oil returning method of refrigerating system

Abstract

The invention discloses an oil returning device of a refrigerating system. The oil returning device comprises an evaporator, an oil loop, an ascending vertical tube, a horizontal cross tube and a gas-liquid separator which are connected successively. The oil returning device also comprises an auxiliary oil returning mechanism which comprises a first pressure transmitter, a second pressure transmitter, a hot gas sprayer nozzle, an electromagnetic valve and an electric control unit; the first pressure transmitter is arranged on a connecting pipeline of the gas-liquid separator and a compressor,the second pressure transmitter is arranged on a connecting pipe of the evaporator and the oil loop, one end of the hot gas spray nozzle is connected to a high pressure exhaust port of the compressorwhile the other end of the hot gas spray nozzle is connected to the side, close to the ascending vertical tube, of the oil loop, and the electromagnetic valve is arranged on the hot gas spray nozzle;the electric control unit is used for controlling the electromagnetic valve to open and close according monitored values of the first and second pressure transmitters. The invention also discloses anoil returning method of the refrigerating system. The oil returning device and the oil returning method disclosed by the invention solve the oil returning problem of the refrigerating system in an extremely low temperature operating condition fundamentally, and the oil returning device is simple in structure, reliable in method, high in degree of automation and safe to use.

Description

technical field [0001] The invention relates to the technical field of refrigeration devices, in particular to an oil return device and an oil return method of a refrigeration system. Background technique [0002] Vacuum freeze dryers, also known as freeze dryers, are usually used for drying sterile preparations or biological preparations. The freeze-drying process of medicines is usually called freeze-drying. The drying stage in the freeze-drying process usually includes sublimation drying and desorption drying in a vacuum environment. The moisture or organic solvent in the medicine is removed by sublimation drying and desorption drying, and the moisture Or the organic solvent freezes or condenses on the coil inside the cold trap of the freeze dryer, and the coil is exactly the evaporator of the refrigeration system of the freeze dryer cold trap. The water vapor or organic solvent vapor generated in the drying process freezes or condenses on the coil to release heat, which...

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Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide an oil return device of the refrigeration system, which can solve the backflow problem of lubricating oil blockage in the refrigeration system under extreme low temperature conditions, thereby overcoming the shortcomings of the existing oil return device of the refrigeration system

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