Dry running protection device and method for electric deep well pump

Abstract

The invention discloses an electric deep well pump dry running protecting device and method, and belongs to the technical field of liquid cargo control. The method comprises the following steps: acquiring instantaneous power P1 of a motor when an electric deep well pump is immersed in a liquid medium and runs stably for the first time; calculating the dry running protecting power of the electric deep well pump in the liquid medium, wherein P= kn*P1; acquiring real-time running power P2 of the motor when the electric deep well pump pumps the liquid medium; and when the real-time running power P2 of the motor is smaller than the dry running protecting power P, determining that the electric deep well pump is in a dry running state. The dry running protecting power P of the electric deep wellpump can be set according to unloading constant kn under different liquid cargo media, when the liquid cargo medium is changed and unloading is carried out again, the circumstance that a deep well pump manufacturer dispatches professional personnel to reset a dry running protecting current preset value is not required, costs for after-sales service and repair of the deep well pump manufacturer arereduced, and time for abnormal operation of a ship is saved.

Description

technical field [0001] The invention relates to the technical field of liquid cargo control, in particular to an electric deep well pump dry running protection device and method. Background technique [0002] LPG (Liquefied Petroleum Gas, Liquefied Petroleum Gas) ships mainly transport petroleum hydrocarbons with propane and butane as the main components or their mixtures, etc. LPG electric deep well pumps are the core components used for LPG loading and unloading on LPG ships. [0003] When the electric deep well pump is working, the initial state is in the liquid cargo medium environment. As the loading and unloading process proceeds, the liquid cargo medium in the LPG ship will gradually decrease, which may make the electric deep well pump outside the liquid cargo medium environment. When the electric deep well pump When there is no liquid cargo medium inside, the electric deep well pump is in a dry running state. At this time, the impeller of the electric deep well pump...

AI Technical Summary

Problems solved by technology

Therefore, whenever the liquid cargo medium is replaced and unloaded again, the deep well pump manufacturer needs to send professional technicians to reset the preset value of the dry running protection current. This process not only increases the after-sales service and maintenance costs of the deep well pump manufacturer, but also wastes and delays Vessel Normal Operating Hours

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