Quantitative analysis of constant pressure difference control mode in heating and air conditioning water systems

Based on the mathematical model of pipe network dynamics, quantitatively analyses the influence of the water system constant pressure difference control method on users’ available differential pressure and circulating pump operating conditions. The results show that in the constant pressure difference control mode, the users who are far away from the constant pressure difference point need to set dynamic pressure difference control devices to ensure the effectiveness of the user regulating valve. The analysis of an example project indicates that the control method of the cold and hot water frequency conversion circulating pumps controlled by end constant pressure difference and unit numbers, compared to the control method of constant speed operation and unit numbers, can reduce the pump energy consumption by 42.9% and 45.7% respectively under cooling and heating conditions, which has good energy saving benefits.