热计量变流量供热系统室外管网动态水力失调与控制

Dynamic hydraulic misadjustment and control for variable flow heat-supply systems

摘要:

热计量供热系统中用户自主调节流量会引起系统管网水力工况的变化,从而导致水力失调.因此,研究用户自主调节变流量供热系统中室外管网的水力工况特性及其控制方法,对于热计量变流量供热系统的节能运行调节具有重要的指导意义.分析变流量供热系统中循环水泵变频调速的控制方式和末端压差控制的热网管路特性;根据自力式压差控制阀可控压差和流量范围,结合工程实例研究热计量系统中用户自主调节所致的变流量供热系统室外管网的水力工况变化,提出以下控制策略:加大末端用户压差设定值或改变最不利压差控制点位置、或同时监控最不利用户和次不利用户压差并在最不利用户和次不利用户处设置分布式加压泵.

Abstract:

To improve the regulation of energy-efficient operation and the hydraulic misadjustment for variable flow heat-supply systems,the dynamic hydraulic conditions and control strategies for the heat-supply network were investigated.The authors analyzed the control mode of circulating pumps with variable speed and the characteristics of pipeline network with pressure differential control for end user in a variable flow heat-supply system.Within the pressure difference and flow range of self-operated pressure differential control valves,the hydraulic operation characteristics of a heat-supply network in a variable flow heating system with users’selfcontrol were studied based on a practical case.The corresponding control strategies were put forward as follows:increasing the design value of pressure difference for end user,or changing the control point of the worst pressure difference,or monitoring the pressure differences of the critical users and fixing distribution pumps at these places.