The self-operated flow control valve can only be used for the reason that the constant flow quality adjustment system is not suitable for the variable flow operation mode.
1, will produce dynamic hydraulic imbalance. When the system performs the flow regulation with the heat source as the active variable flow, or when the flow rate of the system is reduced by other means, the pressure of the pipe network will decrease, and the heat network will become smaller due to the pressure, the near-end user self-operated flow control valve automatic valve The core will open and keep the original flow constant. Due to the special structure and flow rate change of the flow valve, the characteristic resistance S value of the pipe segment changes, and the total characteristic resistance of the network also changes accordingly, and the distribution ratio of the total flow rate in each pipe segment also changes accordingly. Near-end users and remote users cannot change in proportion to changes in total traffic. The traffic change is only the traffic change of the remote user. This will inevitably lead to dynamic hydraulic imbalance of the heating network, and remote users will not meet the heat requirements.
2. When the user adjusts the indoor temperature autonomously according to the requirements, when the self-operated flow control valve and the user need to increase the flow rate after the valve, the flow rate will not increase due to the limitation of the self-operated flow control valve; when the user needs to reduce the flow rate after the valve, the user They will interfere with each other, and the self-operated flow control valve becomes a useless valve that can only consume the power of the pump.
3, need to increase the amount of circulating water flow can not increase. According to the outdoor climate, the circulating water pump needs to increase the circulating water volume. The user flow is not controlled by the control of the self-operated flow control valve. Therefore, the self-operated flow control valve cannot be applied to the heating network that uses the user to actively change the flow rate of the heat network or the heat source to actively change the flow rate. The self-operated flow control valve is only suitable for constant flow quality control systems.
At present, many heating enterprises choose variable frequency, multi-pump, small pump, large pump, small pump to achieve variable flow operation, and the use of self-operated flow control valve for thermal network hydraulic balance is wrong. The heat network with self-operated flow control valve cannot be operated in variable flow mode.