Oilless water chilling unit and air conditioning system

Abstract

The invention discloses an oilless water chilling unit and an air conditioning system. The oilless water chilling unit comprises a compressor, a condenser, an evaporator, a first throttling element and double refrigerant reflux pipelines, wherein the compressor is provided with a refrigerant inlet; the condenser is provided with a liquid outlet; the double refrigerant reflux pipelines are in series connected between the liquid outlet and the refrigerant inlet; the double refrigerant reflux pipelines comprise a first cooling branch and a second cooling branch which are connected in parallel; a first one-way valve is in series connected on the first cooling branch; and a drive device is in series connected on the second cooling branch. According to the oilless water chilling unit disclosed by the invention, refrigerant cooling is adopted inside the compressor, and liquid-state refrigerant separated out from the condenser flows back into the compressor through the double refrigerant reflux pipelines, so that the structure is simple, and maintenance cost is low. Meanwhile, the system avoids influences, on efficiency of a heat exchanger, of lubricating oil, so that efficiency and life cycle of the heat exchanger are not attenuated, unit energy efficiency is high, and an operation range is wide.

Description

technical field [0001] The invention relates to the field of refrigeration equipment, in particular to an oil-free chiller and an air-conditioning system. Background technique [0002] With the increasingly prominent contradiction between economic development and energy supply, energy conservation and emission reduction has become the only way for my country's sustainable energy development. During the high temperature period in summer, the power consumption of air conditioners accounts for more than 50% of the city's peak power consumption. Therefore, improving the operating efficiency of the central air-conditioning unit and reducing the power load has far-reaching economic value and social significance for energy saving and emission reduction. [0003] Under such circumstances, chillers with high chilled outlet water temperature have gradually become the focus of attention in the air-conditioning industry due to their superior energy efficiency indicators. They have broa...

AI Technical Summary

Problems solved by technology

[0005] For conventional screw chillers, when operating in high-temperature cold water conditions, the problem is that screw chillers generally use differential pressure oil supply for lubricating oil circulation to meet the different functions of lubrication, sealing, slide valve control and cooling. Whether the circuit is in normal circulation directly affects the reliable operation of the compressor

However, under the condition of high temperature and cold water, the high and low pressure difference of the system is small, and the oil supply pressure difference is insufficient, which may easily cause oil loss and poor oil supply, which will seriously affect the normal operation of the compressor. Special devices must be considered to force oil supply.

[0006] For conventional centrifugal chillers, when operating in high-temperature cold water conditions, the problem faced is: the cooling of the motor is generally cooled by refrigerant, and the cycle power is based on the pressure difference between the condenser and the evaporator

Mechanical bearings not only produce friction loss, but also lubricating oil enters the heat exchanger with the refrigeration cycle, and the oil film formed on the heat transfer surface becomes a thermal resistance, which affects the efficiency of the heat exchanger. At the same time, the efficiency of the heat exchanger decays more seriously with the service life

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