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.
If the following three conditions occur during the burning and flame out process of a gas-fired boiler, the furnace is likely to blow up.
1.The residual gas content in the furnace reaches the ignition limit at the start-up phase of the furnace.
2.The fuel content in the furnace reaches the ignition limit after several times failure of ignition.
3.The fuel is sprayed out because of the halfway extinction of the flame. And, the temperature of the furnace can not meet the spontaneous combustion condition of the sprayed fuel. However, the content of the sprayed fuel reaches the ignition limit.
The inlet gas pressure is different for different capacity boiler, for example, the pressure for 2 ton steam capacity boiler is about 8~10KPa, while for 4 ton steam capacity boiler is about 12~25KPa. You can tell us the boiler capacity you want, we will help you to get the gas inlet pressure.
The coal-fired boiler refers to the boiler uses various types of coal as fuel and converts the heat of coal to steam or hot water.
There are generally two calculation methods of the circulating water volume of a coal-fired hot water boiler. One is to calculate the hourly water volume of one square meter and the other is to calculate the design parameter volume of every ton. As for the make-up water volume of this type of boiler, it is usually calculated as 1% to 3% of its total circulating water.
If the final temperature of feed water doesn’t reach the saturated temperature after being heated by an economizer, (that is, the feed water has not reached the boiling state), we call the economizer as a nonsteaming economizer. Generally, the final temperature is 30-50℃ lower than the saturated temperature.
Coal-fired boilers refer to boilers that use various kinds of coals as fuel and convert the heat value of coals to steam or hot water.
Some specific parameters should be provided to calculate the theoretical coal consumption of a set of 20 tph coal-fired boiler. If the rated steam pressure is 1 MPa, the heat value of coal is 7000 kcal / kg, the boiler inlet water temperature is 20 ° C, and the boiler thermal efficiency is 80%, the daily coal consumption is 50-56 tons.
Compared with the price of a traditional coal-fired boiler, the operation cost of a gas-fired boiler is relatively high. So, users need to consider the price and quality before purchasing a boiler. For a gas-fired boiler, the energy-saving performance is more important than the boiler price. One year is enough for a gas-fired boiler with good energy-saving performance to save the extra costs of the boiler proper. And, the gas consumption is an important indicator to measure the energy-saving performance of a boiler.
The gas consumption of 10 tph gas-fired boiler is related to technical parameters.
Such as heating surface layout, heat preservation effect, heat loss, water capacity, etc. The calculation formula of gas consumption of 10 tph gas-fired boiler is as follows:
=10 tph gas-fired boiler output÷ thermal efficiency ÷calorific value of natural gas
= 6,000,000 kcal ÷ 0.98 ÷ 8,600 kcal / h = 712 m3
Therefore, the gas consumption of 10 tph gas-fired boiler is 712 m3/ h
The gas consumption of the above gas-fired boiler is calculated at full capacity. In practice, the gas consumption changes with the operation load and operation conditions. In addition, if thermal efficiency of the gas-fired boiler is different, the gas consumption is different, too. The higher thermal efficiency is, the lower gas consumption is.
