Compared with fuels such as coal and biomass, natural gas has a calorific value of 8,500 kcal/cubic, which is relatively high. Therefore, the use of natural gas boilers is more energy-efficient than other types of boilers. But the current price of natural gas is still a bit expensive. How to use natural gas boilers correctly to help save energy? Zhengzhou Fangkuai Boiler Factory will answer for you.
Generally, during the operation of a natural gas boiler, the excess part becomes superheated steam during the combustion process and is discharged with the flue gas, so the flue gas temperature can reach about 220 degrees. Not conducive to energy saving and environmental protection. A tubular waste heat recovery device can be installed at the flue gas outlet, and the flue gas waste heat can be used for heating and pumping into the boiler, which can save more than 5% of natural gas. In this way, on the basis of low heating value, the boiler thermal efficiency can be increased from 88% to 92% and then to 98% to 102%.
1. Improve airflow to meet conditions
Improve the connection conditions between the gas and the air in the gas boiler, the purpose is to increase their contact area. The larger the contact area, the larger the reaction area, which intensifies the combustion. Specifically, the gas and air can be divided into multiple streams, so that the two streams have a certain speed and meet each other; one stream (usually gas) passes through and is immersed in the other stream, and so on.
2. Enhancing mixed disturbance
The combustion of gaseous fuel in a gas boiler is a single-phase reaction. Ignition and combustion are easier than solid fuels, but the combustion speed and combustion perfection are comparable to those of gas and air. There is a close relationship between good and bad. The better the mixing, the more rapid and complete the combustion, and the shorter the flame. Therefore, as long as the flame stability is not damaged, the airflow velocity of the airflow outlet or the combustion chamber should be increased as much as possible, and even a barrier with large resistance such as a baffle should be installed at the inlet to allow it to pass. Hit and explode the flame to increase the disturbance of the air flow. , Strengthen the stirring.
3. Preheat gas and air
Increasing the temperature of the gas and air can enhance the combustion reaction. Therefore, the exhaust heat should be used to preheat the gas and air temperature to increase the combustion temperature and flame propagation speed, thereby strengthening the combustion process.
4. Rotating and circulating air flow
Promoting air rotation can enhance turbulence and mixing. At the same time, a recirculation zone will be formed in the center of the swirling airflow to guide a large amount of flue gas recirculation, which not only strengthens the mixing, but also extends the flow path and residence time of the flue. Reduce the gas in the gas boiler and reduce the loss of incomplete combustion.
5. Flue gas recirculation
In order to increase the temperature of the combustion reaction zone of the gas boiler, part of the high-temperature flue gas can be introduced to the combustion data and mixed with the unburned or burning combustible mixture to increase the combustion intensity. However, it should be noted that the amount of recirculated flue gas should not be too large, otherwise it will dilute the combustible mixing hook due to excessive inert materials, slow down the combustion speed, or even pyrolyze due to lack of oxygen, resulting in incomplete combustion loss of the gas boiler.
