The superheated steam parameters used to reduce the temperature, the different heat sources of modern industry, etc. are fed to the thermal power plant or power station or industrial boiler decompression device (PL high pressure, high-temperature t1 temperature and pressure reduction device) temperature reducer control, which can be realized The production process or steam parameters (pressure P2, temperature t2) are required by the user of the steam device.
It is widely used in thermal power generation, light industry (such as papermaking, printing and dyeing, food), petrochemical industry, and other industries.
The temperature reduction and pressure reduction device is composed of four important parts: a pressure reduction operating system, a temperature reduction system, a safety, and environmental protection work device, and an automatic adjustment control system.
The pressure reducing system consists of a pressure reducing valve 1 and a throttle orifice plate 2. The temperature reducing system consists of a company mixing pipe 3, a nozzle 4, a water distribution valve 5, a device for throttling water resources 6, a stop valve 7, and a check The valve 8 is composed of a safety management protection technical device consisting of the main safety valve 9, a pulse-action safety valve 10, a pressure gauge 11, a thermometer 12, and a steam pipe 13.
1. System pressure: realized by pressure steam control valve. The electric (or pneumatic, the same below) of the reducing valve is connected to the actuator. When the steam pressure in the duct changes, the electric actuator is activated, the reducing valve drives the flaps up and down By adjusting the pressure ratio, the steam pressure in the internal pipeline is maintained within a predetermined range.
2. Temperature reduction system: It is composed of electric control valve, nozzle, mixing pipeline, throttle, throttle valve, etc. After passing through different electric flow control valves, the desuperheating water flows into the desuperheating and pressure reducing valve and is sprayed into the valve body through the nozzle holes of the disc so that the water and steam directly affect the mixing to realize the desuperheating of Chinese steam.
When the pressure of the water supply and desuperheating exceeds the working pressure, in order to make the electric control valve and the nozzle still work normally, install a throttle valve on the water supply pipe before the electric control valve. The pressure of the desuperheating water entering the electric regulating valve is kept within the specified range through the throttle valve.
The electric control valve usually adopts the plunger type, and its valve stem is connected with the electric actuator. When the temperature of the steam in the mixing pipeline changes, the electric actuator is controlled by a temperature adjustment system that drives the movement of the electric adjustment valve stem and adjusts the amount of water injected into the valve body through the nozzle, so that the temperature of the steam in the pipeline is maintained at Within the specified range.
In order to prevent the water pressure of the water supply pipe from being reduced during operation, the sudden drop of steam will cause the water supply pipe to enter the reverse phenomenon through the nozzle. There is a one-way valve in the pipe near the nozzle to reduce overheating.
3. The safety and environmental protection management system of the temperature and pressure reducing device: a spring safety valve (or main safety valve) is used to achieve safety protection. When the steam pressure in the pipeline can exceed the legally permitted value, the safety valve is automatically controlled to open the students to remove the steam. When the pressure is restored to the specified value, the safety valve is automatically closed. Keep the secondary steam pressure within the allowable value to ensure the safe production and operation of enterprise equipment and pipelines.
4. Temperature and pressure reducing device for the thermal regulation system: regulating control valve to realize electric motor and regulating valve, automatic control, remote control or manual control field and other forms.
