Multicompressor parallel connection unit using flooded type shell and tube evaporator

Abstract

The invention relates to a multicompressor parallel connection unit using a flooded type shell and tube evaporator, and belongs to multicompressor units. The multicompressor parallel connection unit solves the problem that liquid refrigerant is returned to the unit along with gas refrigerant existing in the prior art. The multicompressor parallel connection unit using a flooded type shell and tube evaporator comprises a multicompressor parallel connection unit and the flooded type shell and tube evaporator, wherein the multicompressor parallel connection unit is formed by connecting a plurality of compressors in parallel; the flooded type shell and tube evaporator is connected with an expansion valve of the unit; a heat exchange tube is arranged in an evaporator shell; the liquid refrigerant discharged out of the expansion valve enters the shell of the evaporator for being evaporated into gas refrigerant and is returned to the multicompressor parallel connection unit by an interface of the outlet end of the shell; and in the shell, a metal sheet is arranged between the last row of heat exchange tube and the outlet of the shell, and a refrigerant gas and liquid separating device is arranged between the last row of heat exchange tube and the metal sheet. The flooded type shell and tube evaporator disclosed by the invention can ensure that the liquid refrigerant is not returned to the multicompressor parallel connection unit because the metal sheet and the liquid and gas mechanical separating device are adopted in the shell and the tubes, thereby protecting the compressors to normally run.

Description

technical field [0001] The invention relates to a compressor unit, in particular to a multi-compressor parallel unit using a flooded shell-and-tube evaporator. Background technique [0002] In a unit with multiple compressors configured in parallel, at part load (only part of the compressors are running), since the refrigerant oil of all compressors is in the system, the refrigerant oil is mixed with the total refrigerant, and in addition, due to the The refrigerant velocity is low, if the refrigerated oil leaves the compressor and stays inside the heat exchanger, it will affect the efficiency of the heat transfer process and increase the risk of compressor failure due to lack of oil. [0003] The correct delivery of refrigerant in the refrigeration system is very important. The refrigerant must be guaranteed to return to the compressor continuously to prevent damage to the compressor. In addition, the refrigerant must be in a gaseous state before leaving the heat exchanger...

AI Technical Summary

Problems solved by technology

[0005] In order to solve this problem, a metal plate has been added between the last row of heat exchange tubes and the outlet of the flooded evaporator to separate the liquid oil from the gaseous state. This design requires a large design of the evaporator and requires a relatively large Large outer diameter, which will inevitably increase the size of the entire unit, increase the refrigerant charge, resulting in higher costs

In addition, if the liquid refrigerant cannot be completely suppressed, the liquid level of the refrigerant in the evaporator must be reduced, which will reduce the heat transfer efficiency of the heat exchanger

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