大温差离心机组低负荷运行防喘振策略分析

稳态强磁场实验装置水蓄冷系统是国内外具有代表性的大流量大温差水蓄冷系统之一. 系统包含两个3000 m3 的蓄水罐, 为提升蓄冷量双罐均采用了自然分层技术. 由于该技术的特性, 在蓄冷后期, 离心式冷水机组的入口水温会偏低, 这导致系统新增的12 ℃ 大温差机组在试运行阶段多发低负荷喘振故障, 影响了制冷运行的稳定度. 本文首先对离心式冷水机组的喘振机理进行了阐述, 进而分析了在改造前针对该台冷水机组所做的防喘振优化措施; 通过热气旁通改造结合相关参数的合理设置, 避免机组喘振风险; 通过优化 DDC 控制, 优化机组减载能力, 避免了低负荷振动及噪声. 本次改造为系统的安全稳定运行提供了保障.

Analysis on Anti-surge Strategy of Centrifugal Chiller with Large Temperature Difference during Low Load Operation

The steady-state strong magnetic field experimental device water cold storage system is one of the representative large flow and large temperature difference water cold storage systems at home and abroad.The system includes two 3000 m3 water storage tanks,both of which use naturally stratified technology to increase the cold storage capacity.Due to the characteristics of this technology,in the later stage of chilled water storage,the inlet water temperature of the centrifugal chiller will be lower,which causes the new added 12 C large temperature difference chiller to have low-load surge failures during the trial operation stage,which affects the stability of the refrigeration operation.This article first describes the surge mechanism of the centrifugal chiller;then the anti-surge optimization measures for the chiller before the transformation are analyzed.Through the hot vapor bypass modification combined with the reasonable setting of related parameters,the surge risk of the unit is solved; through the optimization of DDC control,the load reduction capacity of the unit is optimized,and low-load vibration and noise are avoided.This transformation provides a guarantee for the safe and stable operation of the system.