Low-energy-consumption condenser variable frequency vacuum system

Abstract

The invention discloses a low-energy-consumption condenser variable frequency vacuum system. The system comprises a condenser, a butterfly valve, a ZJP roots vacuum pump, an atmosphere ejector assembly, a water ring vacuum pump, a separator and a check valve which are sequentially connected through a pipeline. A vacuum breaking device is arranged on the portion, between the ZJP roots vacuum pump and the atmosphere ejector assembly, of the pipeline. The condenser is connected between the water ring vacuum pump and the separator. The butterfly valve, the ZJP roots vacuum pump, the vacuum breaking device, the atmosphere ejector assembly, the water ring vacuum pump, the separator and the check valve are arranged in a cabinet. As the ZJP roots vacuum pump is adopted for replacing an air cooling roots pump, the system is small in energy consumption, constant in drawing speed, low in temperature rise and low in noise; the variable frequency vacuum pump is adopted for automatically adjusting the drawing speed and the compression ratio, the system is prevented from tripping to be shut down, a stand-by pump is prevented from being started, system reliability is improved, energy consumption is reduced, and cavitation is prevented.

Description

technical field [0001] The invention belongs to the technical field of vacuuming, and relates to a vacuum system, in particular to a low-energy-consumption condenser frequency conversion vacuum system. Background technique [0002] Most of the traditional vacuum pumping systems for condensers in thermal power plants are "single-stage water ring vacuum systems" or "hydraulic ejector + water ring vacuum pump composite systems". The pumping speed is less than half of the pumping speed, and the motor cannot automatically adjust with the fluctuation of the system gas volume, and still runs at the maximum speed, resulting in a serious waste of power consumption of the vacuum pump motor; when the ambient temperature rises, the pumping speed attenuation intensifies, and the vacuum pressure of the condenser drops sharply ; Vacuum pump impeller, disc will appear cavitation, resulting in a drop in pumping speed and vacuum pressure; the noise is large, even reaching more than 100 decibe...

AI Technical Summary

Problems solved by technology

[0002] Most of the traditional vacuum pumping systems for condensers in thermal power plants are "single-stage water ring vacuum systems" or "hydraulic ejector + water ring vacuum pump composite systems". The pumping speed is less than half of the pumping speed, and the motor cannot automatically adjust with the fluctuation of the system gas volume, and still runs at the maximum speed, resulting in a serious waste of power consumption of the vacuum pump motor; when the ambient temperature rises, the pumping speed attenuation intensifies, and the vacuum pressure of the condenser drops sharply ;Vacuum pump impeller and disk will appear cavitation, resulting in a drop in pumping speed and vacuum pressure; the noise is loud, even reaching more than 100 decibels

[0003] Chinese patents with application numbers 201310006450.7 and 201310485878.4 disclose a device and method for maintaining vacuum in a thermal power plant condenser. The combined system of air-cooled Roots pump + water ring vacuum pump solves the problem of pumping speed and The pressure is affected by the environment, and the energy saving effect is more obvious

However, when the leakage gas in the condenser changes greatly and the temperature rise increases, the system will trip or start the standby pump, resulting in shutdown or increased energy consumption; the gas after temperature rise is cooled by the intermediate condenser, but after being sucked into the water ring vacuum pump Just try to ensure the pumping speed of the water ring vacuum pump as much as possible, and the cavitation problem of the vacuum pump is not solved, resulting in a decrease in vacuum pressure and pumping speed. increase, the pumping capacity decreases; this kind of maintenance equipment does not have a vacuum breaking device, and the water in the water ring vacuum pump will return to the Roots pump and the system when the power is cut off or shut down instantly, resulting in the emulsification of the gear lubricating oil in the Roots pump; from the equipment The noise of the overall equipment is not considered in the selection and structural design. The noise of ordinary air-cooled Roots pumps even exceeds 100 decibels when the suction volume fluctuates.

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