Automatic control method of large flow seawater pump set for ship exhaust gas cleaning

Abstract

The invention discloses an automatic control method for a large-flow seawater pump set for ship exhaust gas cleaning, including preparation work, a space heater, a self-priming device, pump control and flow control. The preparation work mainly includes two steps. Check, and then connect two power sources, the space heater is first opened to the open position, the space heater starts to run, and the pump is automatically cut off when it is running. , automatic frequency conversion to adjust the frequency of the pump motor, thereby reducing the use of electric power and effectively saving electric energy; adopting multi-stage PI algorithm for automatic adjustment to ensure that the flow rate of each stage can respond quickly and accurately; automatic judgment control to avoid a certain pump always It runs for a long time, and the other pump is rarely used to ensure the trouble-free time of the whole system; when the flow meter fails, it will automatically track the flow adjustment and avoid manual operation.

Description

technical field [0001] The invention belongs to the technical field of ship exhaust gas, in particular to an automatic control method for a large-flow seawater pump set for cleaning ship exhaust gas. Background technique [0002] According to the International Maritime Organization (IMO), according to the MEPC.259(68) resolution on sulfur restrictions for ships in global sea areas, starting from January 1, 2020, ships sailing around the world can only use fuel oil with a sulfur content of no more than 0.5%. One of the effective methods for sulfur oxide emissions is to install an exhaust gas cleaning system (EGCS) for treatment. Regardless of whether desulfurization is added in the desulfurization process or seawater is directly used, the water pump is crucial in the entire system. The main engine of the ship is in different The running state produces different amounts of exhaust gas, that is, the amount of water required to treat ship exhaust gas is also different. This cont...

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Problems solved by technology

[0003] At present, the amount of seawater entering the desulfurization tower is usually controlled by adjusting the opening of the diverter three-way valve, which can effectively treat the exhaust gas. However, the pump is always in the maximum operating state, which requires a lot of power consumption.

[0004] Because the state of the main engine of the ship is constantly changing, and the range of water flow required for exhaust gas treatment is also relatively large, the single-group PID algorithm can quickly, stably and accurately control the flow in a small range, but it cannot be guaranteed when the flow is adjusted by frequency conversion of the large-flow pump. Rapid and accurate response to changes in flow rate between 30-100%

[0005] The exhaust gas cleaning (EGC) system requires redundant configuration for the continuous operation of pumps. Generally, it will manually select which pump to start or automatically start the default main pump. When the running pump fails, it will automatically switch to another pump. Manual selection requires Manual judgment, there are many human factors; starting the main pump by default will cause the main pump to be basically in the running state, the probability of wear and failure is relatively high, and the other pump cannot perform its due function

[0006] When the flow meter fails, the three-way valve cannot be adjusted automatically because there is no flow feedback signal, and the three-way valve can only be adjusted manually to ensure the operation of the exhaust gas cleaning system (EGCS). cumbersome

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