船舶中央冷却水多段比值控制系统设计

针对目前国内船舶中央冷却水系统普遍存在能耗高的问题,提出一种依据三通阀开度变化的实时改变海水变频泵组转速的控制策略。将三通阀开度分为4个区段,每个区段对应1个比值函数,根据比值函数和三通阀开度计算出变频泵组对应的频率。此外,增加smith滞环比较器作为开关函数,避免变频器在安全温度界限附近频繁切换频率对系统产生冲击。试验证明,提出的控制策略不仅实现了海水泵变频节能控制,保证系统稳定、可靠运行,而且显著降低了系统能耗。

Design of ship central cooling water systembased on multiple ratio control

Aiming at the problem of high energy consumption in the ships central cooling water system at present, a control strategy based on the variation of triple valve opening is proposed to change the speed of seawater pump in real time. The triple valve opening is divided into four sections, each section corresponds to a ratio function, according to the ratio function and the triple valve opening, the corresponding frequency of the frequency conversion pump set is calculated. The Smith hysteresis comparator is used as a switching function to avoid the frequency switching frequently near the safe temperature limit. Experiment prove that the proposed control strategy not only achieves frequency conversion and energy saving control of seawater pump, but also ensures stable and reliable operation of the system. At the same time, reduces the energy consumption of the system significantly.