1、 Application and advantages of self regulating liquid level controller for vapor liquid two phase flow
The automatic regulator of vapor-liquid two-phase flow self-adjusting liquid level controller is suitable for water control of pressure vessels such as high-pressure and low-pressure heaters, continuous blowdown flash tanks, raw water heaters, heat supply network heaters and pressure vessels in the electric power industry; it is also applicable to the water level control of various vessels in the petroleum, chemical and steel industries.
The self-adjusting liquid level controller of vapor-liquid two-phase flow has novel conception, advanced working principle, strong self-regulation ability and stable liquid level control; it has no mechanical moving parts, no electrical components, few components and small volume, so its structure and system are simple, easy to install, and its performance is safe and reliable.
Attachment: user feedback:
With the application of a new type of vapor-liquid two-phase flow self-adjusting liquid level controller, the workload of on-site maintenance and operation maintenance is greatly reduced, the maintenance cost is saved and the labor intensity is reduced. Secondly, due to the lack of pneumatic and electric thermal control system and complex thermal auxiliary equipment, the new type of self-adjusting liquid level controller for vapor-liquid two-phase flow reduces maintenance personnel and greatly improves the operation and management level of equipment. Users call it a maintenance free device.
2、 Working principle of self regulating liquid level controller for vapor liquid two phase flow
The self-adjusting liquid level controller of vapor-liquid two-phase flow is a new concept liquid level controller based on fluid mechanics theory and control principle and using the flow characteristics of vapor-liquid two-phase flow. It belongs to self-propelled intelligent regulation and needs a small amount of steam (about 1-2% of the displacement) as the driving source of the actuator. The liquid level controller is composed of regulator (label 4 in the figure) and signal tube (label 2 in Figure). The connection system of the controller on the heater of thermal power plant is shown in the figure. The function of signal pipe is to send water level signal and transmit steam for regulation; the function of regulator is to control outlet water volume, which is equivalent to the actuator in automatic regulation system. The regulation principle is: when the water level of the heater rises, the water level in the signal pipe will rise, resulting in the decrease of the steam quantity sent. Therefore, the steam flow through the two-phase flow in the regulator will decrease and the water volume will increase, and the water level of the heater will drop accordingly. vice versa. Thus, the automatic control of water level of heater is realized.
3、 Product specification and model of self regulating liquid level controller for vapor-liquid two-phase flow:
According to the diameter of the regulator sensor: DN50, DN80, DN 100, DN 130, DN 150, DN 200, DN250, the model can be selected or any size can be designed according to the actual situation.
4、 Installation and commissioning:
（1） Installation of self regulating liquid level controller for vapor liquid two phase flow
1. The sensor must be vertical. The upper branch pipe is connected with the steam balance pipe of the heater, and the lower branch pipe is connected with the horizontal balance pipe of the heater.
2. The steam balance pipe in the heating connecting pipe is higher than the warning water level, and the connection of the water balance pipe on the heater should be lower than the minimum water level.
3. The regulator should be placed horizontally. Special cases may also be placed vertically. Install in the outlet direction as far as possible.
4. The shorter the connecting pipe is, the better, and the fewer elbows are, the better.
（2） Debugging of self regulating liquid level controller for vapor liquid two phase flow
(1) Open all kinds of valves on the drain pipe and check whether the water level gauge and water level controller are sensitive.
(2) it is necessary to keep the drainage capacity of the heating pipe at the maximum load.
(3) when debugging more than two water level controllers in interlocking mode, the sequence is from high pressure to low pressure.
(4) interlock commissioning bypass valve 5, regulating valve 4, water level slowly rising to normal water level, and then open regulating valve 4. Observe the water level and continue to use the regulating valve 4 to close and gradually adjust until the water level can automatically maintain a stable state.
(5) if there is full water in the process of height, the bypass valve 7 can be opened appropriately.
5、 Instructions for ordering self regulating liquid level controller of vapor-liquid two-phase flow:
1. The user shall provide the equipment for which the steam-liquid two-phase flow device is used, and relevant parameters such as pressure, temperature, outlet diameter, etc.
2. Provide the flange of each connecting system, and the connecting pipe has the size.