The high heat transfer of the boiler requires good medium. With the improvement of boiler in the production technology and intelligenlization, gas-fired boilers have more strict requirements for boiler operation medium in order to improve the boiler operating performance, reduce boiler failures and costs.
Gas-fired hot water boilers require high-quality water to improve the boiler performance and extend the service life. If the boiler uses the tap water of water which contains a lot of impurities, magnesium and calcium ions in the water will form white precipitates when the water is heated at high temperatures, which can cause the scaling problem to reduce the heat transfer efficiency of the boiler and bring hidden dangers of the boiler safety.
The food processing needs the steam or hot water to assist the production and improve the efficiency. Usually, the food plant needs the small tonnage boiler, so the coal-fired boiler is not recommended.
The exhaust gas heat loss of coal-fired boiler is caused by the flue gas removed by final stage heat exchanger. The flue gas will take away a part of heat, mainly including the heat taken away by dry flue gas and the sensible heat with water vapor in the flue gas. What’s more, if the combustible gas in the coal-fired boiler is not completely burned, there will be heat loss as well. Therefore, this kind of heat loss mainly depends on the content of incomplete combustion products in the exhaust smoke.
In general, gas-fired boiler uses natural gas to heat water in order to provide heat source for underfloor heating and heating radiator, while condensing gas-fired uses condensation technology to recycle the thermal energy from the exhaust gas.
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.
Generally, there is moisture in heat medium oil. And, the moisture will be evaporated during the heating process of the oil. If the water vapor is not discharged from the thermal oil heater, it will cause the fluctuation of heat medium oil pressure. However, the oil-gas separator can separate the water vapor from the heat medium oil and discharge it from the heater, which ensures the stable oil 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.
