A water level sensor fail on a steam boiler is extremely dangerous. The low water cut of should be tested daily. If the sensor fails the boiler could turn all the water into steam, leaving the boiler dry. Without water in the boiler the flame from the burner would heat up the heating surface to extreme temperatures and would crack and damage the inside of the boiler. But that’s not the dangerous part. If water added to boiler while it is extremely hot. Once water touches the extremely hot heating service, water would immediately start to evaporate into steam. When water evaporates it expands 18x it’s original size. The boiler would explode from the sudden increase in pressure from the inside. Some in some cases, boilers that have exploded out of a building and have landed 100s of feet away.
Not inspecting it often enough can lead to minor issues being missed, which can lead to major issues later and possibly injury.
Not checking a boiler system could have catastrophic results in the form of a boiler explosion. Fuel may explode due to unfound problems. The high temperatures generated by the boiler can also cause problems if the water level drops too low and the trip switch fails.
There are many opinions on the best way to clean a steam boiler. One of the oldest ways is to dissolve a pound of tri-sodium phosphate (TSP) and a pound of caustic soda (lye) in water and pour it into the boiler. Let it cook for a few hours and then drain the boiler. If you can't buy TSP in your town, try a commercial soap called MEX. It works well and will not damage the rubber gaskets found in some boilers. However, before you clean any boiler, check the manufacturer's instructions for their recommendations.
The coal-fired steam boiler is a forced circulation high-pressure single-tube DC boiler. Its operation process includes three processes: the combustion process of the fuel, the heat transfer process of flue gas to water and the vaporization process after water absorbs heat. In order to better control these different processes, the control system should make
the heat of pulverized coal combustion adapt to the requirements of steam load changes and dryness.
Fuel-to-steam efficiency is a measure of the overall efficiency of the boiler. It accounts for the effectiveness of the heat exchanger as well as the radiation and convection losses. It is an indication of the true boiler efficiency and should be the efficiency used in economic evaluations. As prescribed by the ASME Power Test Code, PTC 4.1, the fuel-to-steam efficiency of a boiler can be determined by two methods: the InputOutput Method and the Heat Loss Method.
A steam boiler plant must operate safely, with maximum combustion and heat transfer efficiency. To help achieve this and a long, low-maintenance life, the boiler water can be chemically treated.
The operating objectives for steam boiler plant include:
Safe operation.
Maximum combustion and heat transfer efficiency.
Minimum maintenance.
Long working life.
The quality of the water used to produce the steam in the boiler will have a profound effect on meeting these objectives.
A process load is usually a high-pressure steam load. A process load pertains to manufacturing operations, where heat from steam or hot water is used in the process. A process load is further defined as either continuous or batch. In a continuous load, the demand is fairly constant - such as in a heating load. The batch load is characterized by short-term demands. The batch load is a key issue when selecting equipment, because a batch-type process load can have a very large instantaneous demand that can be several times larger than the rating of the boiler. For example, based on its size, a heating coil can consume a large amount of steam simply to fill and pressurize the coil. When designing a boiler room for a process load with instantaneous demand, a more careful boiler selection process should take place.
Loads vary, and a power plant must be capable of handling the minimum load, the maximum load, and any load variations. Boiler selection is often dictated by the variation in load demand, rather than by the total quantity of steam or hot water required. There are three basic types of load variations: seasonal, daily, and instantaneous.
