The chain grate is the combustion equipment of coal-fired steam boiler. There are three main types and structures: chain belt grate, scale grate and beam grate.
In the adjustment of boiler operation, on the basis of ensuring safe operation, economic operation must also be achieved to improve boiler efficiency. In general boiler units, the efficiency can basically reach more than 92%, and the total loss is less than 8%. The loss is: exhaust heat loss, generally 5-6%, followed by mechanical incomplete combustion heat loss is less than 1-1.5 %, heat loss and ash slag physical heat loss are about 1%. (Physical heat loss for high ash coal ash residue will be greater).
From the point of view of quantification of indicators, the key to improving boiler efficiency is to reduce smoke loss and heat loss due to incomplete combustion of machinery. Pay attention to the flue gas temperature changes. Excessive flue gas temperature will affect the efficiency of the boiler. Too low temperature may cause low-temperature corrosion of the air preheater. Therefore, it is necessary to strengthen the adjustment according to the load changes during operation. When t
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.
The proximate analysis of coal is to dry, heat and burn coal samples as required to get the percentage of moisture, volatiles, fixed carbon and ash in the coal and learn about the characteristics of coal combustion.
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.
The dry bottom hopper is formed by bending the lower part of the water wall of the front and rear walls inward. The main function is to gather, cool and automatically discharge ash. It is also convenient for the connection and sealing of the lower header and the ash well.
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.
Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short- and long-chain hydrocarbons, aromatic hydrocarbons and some sulfur. Volatile matter also evaluate the adsorption application of an activated carbon. The volatile matter of coal is determined under rigidly controlled standards. In Australian and British laboratories this involves heating the coal sample to 900 ± 5 °C (1650 ±10 °F) for 7 min. Also as the rank of coal increases the volatile matter decreases (AMK).
