Constant differential pressure control technique in air conditioning water system (2): Improvement of real flow characteristics of motorized valves

Based on the controllers selection concluded for the four representative air conditioning water systems in the previous paper of this series—Constant differential pressure control technique in air conditioning water system (1): Selection method of self-operated differential pressure controllers, analyses the improvement degree of real flow characteristics. According to the example in this paper, constant differential pressure control technique can improve the real flow characteristics of motorized valves to a great extent, but limited to the flow rate coefficients by actual product specification, the real flow characteristics still have a certain degree of deviation from that in theory under the smaller opening conditions.