In industrial production, most heavy industries utilize industrial boilers to provide the power source for the production end. Industrial boilers cover many regions of the world, and improving boiler efficiency is crucial to the economy, environmental protection and energy efficiency of industrial production. Water, as an important medium for heat transfer in boilers, plays a key role in improving boiler efficiency.

In order to better apply the boiler retrofit technology, the first step is to improve the efficiency of the boiler, and water, as an important medium for heat transfer in the boiler, is crucial in improving the efficiency of the boiler.

A good water treatment program may not only make the industrial boiler industry more scientific and environmentally friendly, but also ensure that the boiler is more efficient, economical and safe in the process of use.

Factors Affecting Boiler Energy Efficiency

Water treatment.

At present, there are many types of water treatment technologies for industrial boilers, but in general they can be divided into two types, i.e., outside-pot water treatment technologies and inside-pot water treatment technologies.

Outside water treatment is mainly in the water into the boiler before the physical, chemical and electrochemical methods of treatment, the purpose is to remove some of the calcium, magnesium and other elements in the water, which can lead to boiler scale or corrosion of the boiler.

In-pot water treatment is to treat the water after it enters the boiler, the main way is to put some chemicals in the pot, and the purpose of the water treatment outside the pot is the same, used to prevent or reduce the boiler is corrosion, scaling.

However, whether it is outside the pot water treatment or inside the pot water treatment, their results are not particularly ideal, so the treatment did not achieve the expected results, often making the boiler after a certain period of time will produce thick scale, or be seriously corroded.

Water Quality.

Because the efficiency of water treatment is less than expected, the water quality after treatment is not up to the requirements, and the water contains excessive calcium and magnesium ions. These are the direct factors leading to boiler corrosion or boiler thick scale.

After the corrosion of the boiler or the boiler is covered with scale, the heat transfer efficiency is very different from before, the increase in heat transfer efficiency is brought about by the decline in efficiency, the boiler thermal efficiency of every 1% drop will be accompanied by an increase of 1.2 ~ 1.5t of energy consumption. Scaling on the boiler's energy efficiency is mainly a reaction to the scaling of the boiler after the material changes, before the scaling of the boiler's material is ordinary boiler steel, and after the scaling of the boiler surface to increase a layer of sulfate, carbonate and silicate mixed with scale. Compared with the thermal conductivity of the two, the latter is only 1/20 to 1/240 of the former.

According to the theory of statistical mechanics, the heat generated by combustion after scaling will be emitted into the atmosphere along with the production of smoke, resulting in a serious loss of heat, not only the loss of power generated by the boiler, but also lead to impure steam and thus increase in the rate of sewage. Theoretically, 1mm of scaling brings about a loss of 3% to 5% of coal combustion.

The boiler corrosion may lead to the damage of the important components of the boiler, which will bring economic losses. In addition, the purpose of alkalinity removal of boiler water can not be effectively accomplished, making the boiler water alkalinity exceeds the standard, which will directly lead to the boiler discharge rate exceeds the standard. Therefore, the discharge rate of China's industrial boilers has always been in the 10% to 20% high, and once the discharge rate increases by 1 point, it will also lead to an increase in the amount of coal combustion by 0.3-1 point, and the corrosion of the boiler will also become more serious. Therefore, the improvement of water treatment technology is urgent, for this reason, it is necessary to carry out a more profound analysis, for the brainstorming to provide some useful ideas. Once the water quality can meet the standard, then the economic efficiency of the industry will be greatly improved.

Boiler Heat.

Because of the impact of water quality leads to the production of boiler scale, which will directly cause the ineffective loss of heat, so the effective utilization of boiler heat becomes very low, in addition, because of heat loss makes the boiler water temperature and the average temperature difference between the economizer increased, resulting in increased loss of exhaust heat. The result is an indirect increase in fuel loss, 10% of the ineffective fuel is so caused. The loss of tens of thousands of tons of fuel each year prompted the update of water treatment technology has become critical, so that not only to improve economic efficiency, but also able to reduce the rate of emissions for the country's socio-economic and environmental protection of the world have played a fundamental role. And the energy saved and increased boiler energy efficiency, the enterprise can be put into the reproduction process, creating a considerable amount of value.

Improvement Strategies to increase boiler energy efficiency

Boiler Water Treatment Status:

The currently used water treatment technology outside the pot mainly relies on the sodium ion exchange method, and this method is mainly used in the softening treatment stage of water treatment. By flowing the water through the ion exchanger containing Na, H and other cations, so that Ca, Mg and other ions are adsorbed by the exchanger, and Na, H and other ions into the water, so that the water to achieve the effect of softening. However, this method is slightly more difficult in the treatment of anion HCO3-, and it is not possible to make the content of anions lower than expected, so that the alkalinity of the water can not be effectively reduced.

Improvement Measures:

To this end, the need to provide new water softening program, and reverse osmosis water treatment technology is now a better alternative, the principle of the technology is to use semi-permeable membrane permeability properties of the water as much as possible to remove the salt, so that the salt and calcium in the water, magnesium can be removed as much as possible clean. According to the existing experimental data show that the method in the treatment of raw water, can make calcium, magnesium, iron and other ions removal rate of more than 95%, after the secondary osmosis technology after treatment of the water quality in all aspects of the indicators have been able to reach the boiler scale-free operation standards, not only to enhance the boiler's energy efficiency, but also reduce the boiler's sewage rate, so that the emission of pollution to meet international standards more quickly. standards.

In addition, the recycling of boiler water condensate and sewage water is a good idea for water treatment improvement. The advantage of this is not only to reduce the loss of heat and improve the energy efficiency of the boiler, but also to reduce the emission of pollution and reduce the sewage rate. Through the discharge of sewage recycling treatment, the sewage in the atmosphere of polluting substances for the clear, restore the sewage, and then processed for discharge, can effectively reduce the emissions of atmospheric pollution. Indirectly, it can also make up for the loss of heat, so that the heat will not be lost for nothing.

Specific measures are to treat and utilize condensate and sewage water by adding a sewage expander to the boiler, to deaerators, drying cylinders, ovens and other equipment for heat recovery.

Then there is the enterprise should be further relevant staff for pre-service knowledge training and regular learning, so that the staff of the boiler water treatment has a clear understanding, so that they can put their energy into the knowledge of the work 4, to do a good job. Regular cleaning of the boiler's scaling, do not let the scale on the boiler's energy consumption has a greater impact, reduce the boiler to produce too much heat loss.

When the boiler heating surface has a large corrosion, the boiler replacement to avoid accidents causing economic losses, boiler scaling up to 1mm when the descaling operation to ensure that the full utilization of energy and heat.

Responsibility system for each position in the enterprise, once the problem occurs, the responsibility will be implemented to the individual, the operation of the relevant equipment for water treatment to the professionals with a certificate to carry out standardized operations, reasonable discharge of pollutants, so that the water treatment process can be more scientific, standardized, professional, and to ensure that the water quality can always be in a higher range of indicators.

The maintenance of the boiler is also essential. In the process of boiler work, the temperature of the boiler is much higher compared with the ambient temperature, which is one of the reasons for heat loss. As we all know, heat energy is always transferred from a high place to a low place. If you want to avoid the loss of heat energy in this area, you should do the maintenance of the boiler in advance, by insulating the boiler and setting up an effective insulation layer, which is the best program to make the heat loss reduced.

Conclusion

Water treatment plays a fundamental role in the transformation of boiler technology, the current stage needs to be improved first. However, it is impossible to improve the water treatment in one step, and it requires multiple parties, multiple steps, and gradual improvement to achieve the desired results. For this reason, the analysis of water treatment and related factors is very meaningful, the results of the analysis of can guide the practical process of water treatment, for which the adverse factors to develop a perfect treatment measures to ensure that industrial boilers to ensure safe and stable work while improving the performance and energy efficiency of boilers in all aspects. This will not only give a solid foundation for the safety of heavy industry, but also improve the economic efficiency of the plant.