Compared with fuels such as coal and biomass, the calorific value of natural gas is 8500 kcal/m3, which is still relatively high. Therefore, the use of natural gas boilers is also more energy-efficient than other types of boilers. However, the price of natural gas is still a bit expensive at present. How can we use natural gas boilers correctly to help save energy? Zhengzhou Fangkuai Boiler Factory is here to answer you.
During the operation of a general natural gas boiler, the extra part becomes superheated steam during the burning process and is discharged with the flue gas, so the exhaust flue gas temperature can reach about 220 degrees, which is not conducive to energy saving, but also Not friendly to the environment. We can install a tubular waste heat recovery device at the flue gas outlet, and use the flue gas heat to heat and prepare to be pumped into the boiler, which can save more than 5% of natural gas. In this way, the boiler thermal efficiency can be increased from 88% to 92% to 98% to 102% based on the low calorific value.
1. Improve the conditions for airflow encounters
The purpose of improving the communication conditions of the two air streams of gas and air in a gas boiler 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 air streams have a certain speed and meet each other; one air stream (usually gas) passes through and is submerged in the other air stream, and so on.
2. Strengthen mixing and disturbance
The combustion of gaseous fuels in gas-fired boilers is a single-phase reaction. It is easier to ignite and burn than solid fuels, but its combustion speed and combustion perfection are closely related to the mixing of gas and air. The better the mixing, the more rapid and complete the combustion, and the shorter the flame. Therefore, as long as the stability of the flame is not destroyed, the airflow velocity in the airflow outlet or combustion chamber should be increased as much as possible, and even barriers with high resistance such as baffles should be installed at the entrance to allow it to hit and blast the flame to increase the disturbance of the airflow. , To strengthen the mixing.
3. Preheat gas and air
Increasing the temperature of gas and air can strengthen the combustion reaction. Therefore, the waste heat of the exhaust smoke should be used to preheat the gas and air temperature, so as to increase the combustion temperature and flame propagation speed, so that the combustion process can be strengthened.
4. Rotating and circulating air flow
Promoting the rotation of the airflow can enhance turbulence and mixing. At the same time, a recirculation zone will be formed in the center of the rotating airflow to guide a large amount of flue gas to recirculate and circulate, which not only strengthens the mixing, but also prolongs the flow route and residence time of the flue gas in the gas boiler and reduces the loss of incomplete combustion.
5. Recirculation of flue gas
In order to increase the temperature of the combustion reaction zone of the gas boiler, a part of the high-temperature flue gas can be led to the combustion chamber to mix it 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 too much inert material, which will slow the combustion speed, even lack of oxygen and pyrolysis, resulting in incomplete combustion loss of the gas boiler.
