Thermodynamic imbalance in heat-insulating pipe central heating system should be analyzed in detail. Under normal conditions, the problem of temperature imbalance can be well handled by choosing optimal heat source equipment, ensuring adequate heat supply, or changing user heat exchangers to improve the heat exchange efficiency of heat exchangers after checking and confirming the reasons.
Hydraulic imbalance of heat preservation pipe central heating system is becoming more and more common and diverse, including:
The application of conditioning valve. The use of conditioning valve is an important measure to alleviate the thermal imbalance of central heating system and ensure the hydraulic balance. There are three main types of regulating valves used in heat preservation pipeline network: static regulating valves, dynamic flow equalizing valves and dynamic differential pressure equalizing valves.
In detail, the static conditioning valve plays a fundamental role in hydraulic balancing. Its working principle is to adjust the resistance in the pipeline to reach the purpose of orifice plate conditioning, and then balance the resistance in the insulation pipe network. Therefore, the static conditioning valve is an artificial conditioning operation.
Dynamic flow equalization valve, also known as self-operated flow control valve, is an important equipment to complete the hydraulic equalization of the pipeline network. Detailed working principle is that according to the different pressures of the front and back of the valve, the valve stops automatically opening large or small to ensure that the flow is constant and the flow is controlled reasonably. Constant flow conditioning valve is a new type of dynamic flow control equipment, which can complete the flow self-regulation of each loop and ensure the hydraulic balance of the thermal pipe network. Compared with the original conditioning valves, all series of constant flow conditioning valves can be equipped with electric actuators, and connected to the automatic control system of the heating network to complete the automatic control of the heating system. Compared with the original manual control valve, the constant flow control valve is more convenient, simple and intelligent, and the cost of the device is not high.
Dynamic pressure differential equalization valve, also known as self-balancing valve, is a kind of system which provides data reference for the regulation of thermal pipe network after measuring and debugging the pressure difference. The detailed working principle is that when the flow rate in the insulation pipe changes, the valve core of self-balancing valve will move up and down accordingly. Thus, the flow surface of self-balancing valve will be moved up and down. The cumulative flow coefficient will be different, but at different locations it will always ensure that the spool and seat are balanced and that the differential pressure value remains unchanged. In general, the dynamic differential pressure equalization valve should stop the device at each control node to complete the overall monitoring of the thermal network.
(2) Application of pressure pump. The use of pressurized pumps mainly refers to the use of pressurized pumps at the disadvantageous end of heating, which is another important measure to deal with the hydraulic imbalance of the thermal pipe network and ensure the hydraulic balance. This is because the practice head and flow of circulating water pump in heating system are not fixed and have been adhering to sufficient conditions, so in practice, there will be insufficient practice head and flow of circulating water pump in heat insulation pipe network, which will inevitably lead to the lack of capital pressure head or flow at the disadvantageous end of distant heating. Therefore, installing water pumps in heat exchanger stations of unfavorable end users will help to ensure the heating flow of unfavorable end users.
It should be noted that the installation of pumps in heat exchanger stations should be carefully selected and reasonably equipped to prevent the flow rate affecting other users around them from forming more serious hydraulic imbalances, such as "water grabbing" problems. To select pumps, one needs to understand the known parameters in the heat exchanger station, and the other needs to understand the detailed information of pressure head and flow. Separation of the two is used as a reference criterion for selecting pumps. Usually, small pressurized pumps are enough to meet the needs of most users. At present, the types of pumps are rich and varied, and the technology is mature. There are small flow, small lift, low noise, maintenance-free pumps, and three-speed variable-speed pumps with higher technical content, and continuously variable-speed pumps with frequency conversion (flow, temperature, pressure, differential pressure).
(3) The optimization of heating system equipment. The optimization of heating system equipment is mainly concerned with aging, unqualified and unreasonable pipes, boilers with low heating efficiency and heat exchangers with low heat energy conversion rate, etc. to stop the optimization and transformation, to improve the heat of heat preservation pipe central heating system, to reduce the loss and loss in heat storage, to improve the conversion rate of secondary heat energy and to reduce it. Presentation of thermodynamic imbalance.
