How to improve the thermal efficiency of portable furnace?

National combustion energy for gas boiler, in order to save fuel, improve the thermal efficiency of the boiler, to start from the following aspects.

1, the use of flue gas waste heat recovery technology, reduce smoke loss.

The main factor affecting the heat loss of exhaust is exhaust temperature. The higher the exhaust temperature, the greater the exhaust heat loss.

At present, most of the newly built boilers are equipped with flue gas waste heat recovery device, such as coal economizer, semi-condensing or fully condensing flue gas waste heat recovery device, these measures can effectively reduce the exhaust temperature, improve the thermal efficiency of the boiler.

2. The fluctuation of the range value of excess air coefficient.

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 combustion, but is discharged after heating, and the heat loss of smoke exhaust increases.

If the cold air entering the furnace continues to increase, beyond a certain limit, the temperature of the furnace will decrease, and the loss of incomplete combustion will increase.

When the excess air coefficient is too low, the fuel cannot completely burn due to insufficient oxygen, resulting in an increase in incomplete combustion loss. However, long-term serious incomplete combustion will lead to the heating area of the boiler carbon, affect the heat transfer efficiency, smoke exhaust loss continues to increase.

Therefore, reasonable control of air-fuel ratio, as far as possible to reduce exhaust heat loss Q2 and incomplete combustion loss Q3, is another key point to improve the thermal efficiency of boiler.

3, strict control of boiler water quality, scientific control of scale.

Boiler feed water will contain a variety of impurities and calcium, magnesium and other scaling substances, the boiler will inevitably scale. The thermal conductivity of scale is very low, so once the heating surface scale, due to the increase of thermal resistance, boiler exhaust temperature will rise, exhaust heat loss will increase.

Test data show that 1 mm scale on the boiler heating surface will increase the heat loss of exhaust about 2-4%, the thicker the scale on the boiler heating surface, the greater the thermal resistance, the more the boiler thermal efficiency will decline.

The scaling of boiler not only reduces the thermal efficiency of boiler, but also increases the temperature of boiler heating surface, resulting in damage of heating surface and even boiler explosion accident.