An Interlock in the boiler’s control system is a programmed or hardwired condition that forces a device to be in a pre-determined or permissive state before the process can continue.
Depending on design pressure, fuel type, either liquid, gas or solid, all steam boiler require interlocks to sequence the operation and to prevent damage to the boiler. Examples of such devices are High or Low Boiler Drum Water Level, Low Boiler Feed Pump Pressure, High or Low Fuel pressure, High or Low Atomization pressure (oil fired), Proof of Ignition, Proof of Flame, FD and/or ID (solid fuel) Fan Motor Operation or combustion air pressure, Damper or Valve position and High Boiler Steam Pressure as well as O2 and furnace temperature.
Boiler output refers to the maximum continuous output of the boiler under rated parameters (pressure, temperature) and certain efficiency. For steam boilers, it is called rated evaporation, and the unit is tons/hour; For hot water boilers, it is called rated heat production, and the unit is MW.
What are the main factors affecting the output of gas-fired boilers? According to the analysis of ZOZEN Boiler engineers, there are many reasons for the insufficient output of gas-fired boilers,
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(1) The boiler and all auxiliary equipment are installed, and all tests such as ball passing test, hydrostatic test and air tightness test are qualified.
(2) All rotating devices, feed water pumps, condensate pumps, salt solution pumps, blowers and induced draft fans for coal conveying, combustion and ash removal are qualified for trial operation.
(3) The fuel and water supply are guaranteed, the steam, water and flue gas piping system are normal, and the connection unrelated to the boiler to ...
Among the commonly used steam boilers, those under the pressure of 3.825 MPa are called medium pressure steam boilers, and those under the pressure from 9.8 MPa to 13 MPa are called high pressure steam boilers. Different boiler pressures have different requirements for water quality. Generally, medium and low pressure steam boilers need to supplement softened water, and softened alkali-free water, while high pressure boilers need desalted water. The different water qualities require different corresponding treatment equipment.
The boiler water level gauge is a detection instrument that shows the water level of the boiler, and it is one of the important safety accessories of the steam boiler.
Drum boiler refers to boiler equipment with boiler drum, which is an important pressure component in natural circulation boiler and the connecting hub of the three processes of boiler heating, vaporization and overheating, and plays a connecting role. Water becomes qualified superheated steam in the boiler, which goes through three processes: heating, vaporization and overheating. Heating from feed water to saturated water is a heating process; The vaporization of saturated water into saturated steam is a vaporization process; Heating saturated steam into superheated steam is an overheating process.
When it is found that the boiler steam pressure can't rise, the first thing we should do is to check whether the water pump of the gas-fired steam boiler works and how much the pressure of the water pump of the gas-fired steam boiler can reach. When installing the water pump of the gas-fired steam boiler, a pressure gauge is installed on the water pump. This is because, if the gas-fired steam boiler does not add water, it can be detected whether it is caused by the water pump.
Different steam pressures correspond to different steam temperatures.
1. The steam temperature of low-pressure boiler is mostly saturation temperature or not higher than 400℃.
2. The outlet pressure of medium-pressure boiler is 3.8 ~ 5.4 MPa, and the commonly used steam temperature is 450℃.
3. The outlet pressure of sub-high pressure boiler is 5.4 ~ 9.8 MPa, and the common steam temperature is 540℃.
