Does the flue gas condensate produced by the gas boiler need to be treated?

In the current boiler market, there are more and more types of gas-fired boilers using energy-saving technologies, and condensation technology is one of them. By adding a condenser at the end of the boiler, a large amount of latent heat is released when the high-temperature flue gas passes through the condenser, and is supplied to the boiler for reuse.

Condensed water refers to liquid water formed by water vapor (ie, gaseous water) during condensation, which is a physical change. Today, Fangfang Boiler will unveil the treatment of condensate for you!

1. There are two main reasons why gas boilers produce flue gas condensation water.
(1) The water vapor in the flue gas condenses into water when it is below the dew point temperature;
(2) The boiler has high thermal efficiency and low exhaust gas temperature. The exhaust temperature of the boiler under the rated load is slightly higher than the dew point temperature of the flue gas. Under the condition of long-term operation with low load, the flue gas temperature is lower than the flue gas dew point temperature, and condensed water will flow out from the tail heating surface of the boiler. , the boiler is discharged from the rear smoke box.

2. What are the components of gas boiler flue gas condensate?
The gas boiler generates condensed water during operation. The main components of the condensed water include: water produced by natural gas combustion, sulfur oxides formed by combustion of sulfur in natural gas impurities, acidic substances formed in water, and nitrogen in the air under high temperature conditions. The nitrogen oxides formed by the oxygen in the air are dissolved in the acidic substances generated by the water.

3. There are too many condensed water in the gas boiler. How to deal with it?
       When the gas boiler is in operation, especially when the cold furnace is started, the flue gas condensed water is often generated at the heating surface of the boiler tail and the rear smoke box, so that the furnace worker mistakenly believes that the boiler leaks.
       The condensed water generated by the gas boiler during operation should be discharged out of the boiler in time, because if the condensed water accumulates too much, it will affect the normal operation of the boiler, which will cause water leakage at the connection between the rear smoke box door cover and the rear smoke box flange.
       Specific measures include:
       (1) The boiler is provided with a condensate drain at the rear smoke box
       In order to enable the condensed water to be discharged in time, the discharge port is generally not provided with a valve, and a water seal should be provided to prevent the flue gas from escaping from the tube.
       (2) Smoke box outlet setting takeover
       After the boiler flue gas exits the smoke box and enters the chimney, since the heat dissipation of the chimney is still cooling, the water vapor in the flue gas is still condensed on the chimney wall, forming small water droplets flowing down the chimney wall, so it should be in the smoke box. The outlet is set to allow the condensate to drain into the trench or any drainage system.
       Excessive condensate of gas boiler flue gas should cause concern. Although condensed water production is unavoidable, excessive condensed water is generated, which will inevitably affect the safe operation of the boiler.

4. Does the flue gas condensate of the gas boiler have any pollution problems? Do you need special treatment? According to the composition analysis of the condensed water, we can know that the condensed water is acidic. The pH value of condensed water is mainly related to the sulfur content of natural gas. At present, domestic natural gas is mainly from four atmospheric fields, and the sulfur content is unknown. If you are interested, you can buy some PH test paper to measure the PH value of the boiler condensate.
In general, the condensate pH of a cast aluminum heat exchanger is slightly higher than that of stainless steel (equivalent conditions).
But although the condensate has a certain acidity, it has little effect on the environment. Do not believe that the condensate is collected in a bucket, added with alkaline substances and then poured into the sewer.

Because the condensate is somewhat acidic, it is diluted very lightly after entering the sewer system, and its effect is minimal. Moreover, today's residential sewers are made of plastic pipes, and even condensed water that has not been diluted will not affect the pipeline.

So we can ignore the environmental impact of this condensate. There is no need for special handling.

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