1. Adopt waste heat recovery technology of flue gas to reduce smoke exhaust loss.
The main factor that affects the heat loss of exhaust gas is exhaust gas temperature.The higher the exhaust temperature is, the greater the heat loss is.At present, most of the newly built boilers are equipped with flue gas waste heat recovery devices when they leave the factory, such as economizer, semi-condensing or fully condensing flue gas waste heat recovery device. These measures can effectively reduce the exhaust temperature and improve the thermal efficiency of the boiler.
2. When the excess air coefficient is too high, it is equivalent to inhaling excess cold air into the furnace. This excess cold air does not participate in the combustion, but is discharged after heating, and the heat loss of exhaust smoke increases.
If the cold air entering the furnace continues to increase, beyond a certain limit, the temperature of the furnace will decrease, and the incomplete combustion loss will also increase.
When the excess air coefficient is too low, the fuel cannot be completely burned because it cannot get enough oxygen, resulting in the increase of incomplete combustion loss.However, long-term serious incomplete combustion will lead to carbon in the heated area of the boiler, affect the heat transfer efficiency, and continue to increase the smoke exhaust loss.
Therefore, it is another key point to improve the boiler thermal efficiency to reasonably control the air-fuel ratio and reduce the exhaust heat loss Q2 and incomplete combustion loss Q3 as far as possible.
3. Strictly control the water quality of the boiler and scientifically control the scale.
Boilers feed water will contain all kinds of impurities and calcium, magnesium and other scaling substances, boiler will inevitably scale.The thermal conductivity of scale is very low, so once the heating surface is scaled, due to the increase of thermal resistance, the temperature of boiler exhaust will rise, and the heat loss of exhaust will increase.
The test data show that when 1mm scale is formed on the heating surface of the boiler, the heat loss of exhaust gas will increase by about 2% ~ 4%. The thicker the scale is on the heating surface of the boiler, the greater the thermal resistance is, and the more the boiler thermal efficiency will decrease.
Boiler scaling not only reduces the thermal efficiency of the boiler, but also increases the temperature of the heating surface wall of the boiler, resulting in heating surface damage, and even causing boiler explosion accident.
Therefore, the use of high quality soft water treatment device, in strict accordance with the process of running boiler water softening treatment device, control boiler water quality, can delay the formation of scale.
At the same time, it is also very important to carry out real-time control of boiler scale, grasp the situation of boiler scale, and clean up scale when necessary.
4, strengthen heat preservation, prevent running and leaking, reduce heat loss.
Because the temperature of the boiler body and the steam and thermal pipe system is always higher than the air temperature in the boiler room, some of the heat will be lost to the surrounding air in the way of radiation and convection, which becomes the heat dissipation loss of the boiler.Therefore, when the insulation layer of the boiler and thermal pipeline system is damaged or found to run and leak, it should be repaired in time to reduce the heat dissipation loss.
5. Measures to improve boiler operation thermal efficiency in foreign countries:
(1) A large number of condensing or semi-condensing technologies are used to recover waste heat of flue gas, so as to significantly reduce the exhaust temperature and minimize the heat loss of exhaust gas.
(2) The combustion intelligent control device is adopted to automatically adjust the combustion air-fuel ratio according to the continuous monitoring of the flue gas composition, so as to ensure that the air-fuel ratio always maintains the optimal state, so as to basically avoid incomplete combustion heat loss and continuously reduce the heat loss of exhaust smoke.
(3) The Internet of Things technology is adopted to supervise the scale situation of online boilers, and scientifically guide water quality control and scale removal.