Method for rapidly switching multi-stage centrifugal low-temperature liquid pump of air separation device

Abstract

The invention discloses a method for rapidly switching a multi-stage centrifugal low-temperature liquid pump of an air separation device. The method comprises the following steps that a low-temperature liquid pump rapid switching interlocking logic is added, a main pump serves as an output pump to normally run, a standby pump is used for low-pressure low-speed circulation standby application, and the standby pump is put into rapid switching interlocking; when the outlet pressure of the main pump is lower than a system low report value and the rotating speed is lower than 75% of the rated rotating speed of the main pump, the main pump is logically judged to break down, and rapid switching is triggered; and at the moment, a standby pump frequency modulation instruction rapidly copies a main pump frequency modulation input value, a pump rear backflow valve of the main pump is completely opened, a pump rear backflow valve of the standby pump is completely closed within 10s, the standby pump output rapidly tracks the state before the main pump breaks down, the standby pump replaces the main pump to serve as a new output pump, and pump switching is completed. According to the method, rapid switching of the pump can be achieved, disturbance to the system in the switching process is greatly reduced, continuous supply of products is guaranteed, the risk of machine tripping of product users is avoided, and safe and stable running of a power station is guaranteed.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for quickly switching multistage centrifugal cryogenic liquid pumps of an air separation unit. Background technique [0002] Some products of the air separation unit of the IGCC power station are pressurized by a multi-stage centrifugal cryogenic liquid pump, vaporized through a heat exchanger, and then sent to the user. The air separation unit is generally equipped with two low-temperature liquid pumps for the same medium, one is used as the output pump, the return flow is fully closed and the high speed is operated, and the output is adjusted by changing the speed through the frequency modulation command, and the other is circulated through the return valve at low pressure and low speed for standby. [0003] If the output of the output pump drops rapidly due to a fault or the pump jumps during operation, it will take a period of time for the operator to find ...

AI Technical Summary

Problems solved by technology

This process takes a long time, and the risk of product user device jumping is extremely high

[0004] If normal manual switching is required, the conventional operation needs to adjust the frequency conversion value of the output pump and the standby pump and the opening of the return valve after the pump synchronously. machine risk

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