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Condensing wall-hung boilers and floor heating have joined forces to become the future development trend
2021/6/4 11:50:57

Condensing wall-hung boiler is a general term for wall-hung boilers that use high-calorific value condensation technology. Its main advantages are: it satisfies the heating and domestic hot water needs of the family at the same time. Compared with central heating, ordinary gas-fired wall-hung boilers and other heating systems The most energy-saving; not limited by the traditional heating time, users can independently control the indoor temperature; easy to use, the highest degree of comfort.

First of all: As a mature heating terminal system, the water floor heating system has a low water supply temperature, usually around 40℃~50. From the comparison of the main performance of the condensing wall-hung boiler and the gas, it can provide users with more energy-saving and environmentally friendly heat sources that can adapt to special conditions, especially suitable for floor heating needs, but it is also not widely popular due to its high price. This characteristic of the water supply temperature of the water floor heating system determines that this temperature characteristic must be considered when the wall-hung boiler is combined with the water floor heating system. Compared with ordinary wall-hung boilers, condensing wall-hung boilers can be more conveniently and perfectly combined with water floor heating.

There are two important reasons:

1. According to the energy efficiency standard of domestic wall-hung boilers-GB20665-2006, when the temperature of supply and return water is 80/60, the thermal efficiency of popular wall-hung boilers at full load is about 90%, and the condensing wall-hung boilers are at full load. The thermal efficiency in the state is about 99%. According to the relevant regulations of EN483, when the supply and return water temperature is 50/30, the thermal efficiency of the condensing wall-hung boiler is about 105%% under full load, and the maximum can reach 109%. The 50/30supply and return water temperature just meets the water temperature requirements of the water floor heating system. There is no need to run the condensing wall-hung boiler in a low-efficiency high-temperature section, which can give full play to the energy-saving effect of the condensing wall-hung boiler.

2. For the ordinary wall-hung boiler system, such as the operating cost that users are most concerned about, the environmental protection of the flue gas emission of the wall-hung boiler, and the stability of the system. With the continuous development of wall-hung boiler technology, these problems can now be solved by the wall-hung boiler with high heating value condensation technology. Now we compare the main functions of these two products on the wall-hung boiler market in terms of incineration methods, technical characteristics, and process materials as follows:

The first category of products: wall-hung boilers with ordinary burning techniques

Combustion method: Proportional adjustment burner is used-that is, a proportional adjustment method with adjustable gas volume and non-adjustable air inlet volume. As the wall-hung boiler is combusted in proportion to gas and vulgarity under working conditions, it is very important whether the wall-hung boiler can achieve a complete combustion mixing ratio. Working under this kind of complete combustion and inclusion ratio, the combustion efficiency is high and the pollution emission index is low. The disadvantages of ordinary combustion technology wall-hung boilers are that the gas/air cannot reach the complete combustion mixture ratio from time to time, and the excess air coefficient is relatively high under departmental load, so the heat loss taken away by the flue gas is relatively large, and the pollutant emission index is relatively high. The thermal efficiency is lower under partial load than under full load conditions. Domestic products usually have a thermal efficiency of around 90% under full load, and around 85% under light load. The thermal efficiency and energy saving of the heating system are considered in accordance with the domestic wall-hung boiler energy efficiency standards. The normal full-load efficiency is at the left and right condensing type, but according to the highest energy efficiency standard. The exhaust temperature of such products is above 120, and the content of harmful nitrogen oxides and carbon monoxide in the exhaust gas is about Nox: 150-200mg/kwhCO: 120-200mg/kwh.

Ordinary wall-hung boilers are mostly made of copper and aluminum fins, with a service life of 10-15 years. Due to its technical content and materials, the price is relatively moderate. At present, most domestic users of wall-hung boilers use these products because of their price and gas adaptability.

The second category of products: wall-hung boilers with high heating value condensation technology

This type of wall-hung boiler uses the worlds advanced condensing technology to recycle the waste heat in the flue gas, and its incineration method is fully premixed. In addition, the exhaust gas temperature of the condensing wall-hung boiler can be as low as about 40, and the latent heat of water vapor in the flue gas is basically fully absorbed and utilized, so the thermal efficiency can be greater than 100%, up to 109%. The combustion is more complete, the energy consumption is very low, and the environmental protection index is very good. The combustion chamber of the wall-hung boiler is made of stainless steel or silicon-aluminum alloy materials, which can overcome the acid corrosion problem. Therefore, there is no limit to the return water temperature of the wall-hung boiler, and the service life is longer than 20 years. The environmental protection and energy saving performance are excellent. Because the material is corrosion-resistant, it can be applied to any heating system: radiators, floor heating, fan coils. The utilization rate of this product in the Western European market is around 60%.

Due to the two major benefits mentioned above, coupled with the gradual increase in national energy-saving and emission reduction policies, the increasing maturity of condensing technology and the more reasonable price, we believe that new condensing wall-hung boilers will be available in the Chinese market in the near future. Widely used.

Secondly: Condensing wall-hung boilers can be perfectly combined with the advantages of water floor heating

According to the data, when the outdoor temperature is lower than -3, the system demand temperature of the wall-hung boiler will be lower than the dew point temperature of the flue gas by 57. At this time, the ordinary wall-hung boiler must use a water mixing device to lower the water supply temperature and increase the return water. The temperature is to avoid the long-term lowering of the dew point temperature inside the ordinary wall-hung boiler, and to meet the water supply temperature necessary for the water floor heating system. However, the condensing wall-hung boiler does not need to adopt a water mixing device and can directly provide hot water to the water floor heating system.

Because the thermal efficiency of the condensing wall-hung boiler is about 15%-20% higher than that of the ordinary wall-hung boiler, the thermal efficiency of the water floor heating system is about 12% higher than that of the ordinary radiator heating system. Therefore, the "condensing wall-hung boiler + water floor heating system" is more The thermal efficiency of wall-hung boiler + ordinary radiator heating system is about 30% higher. At the same time, the emission of pollutants in the flue gas of the condensing wall-hung boiler is also greatly reduced.

The load of the heating system changes with the change of outdoor temperature. At the same time, the heating requirements of the users are different, and the heating load is also different. Ordinary wall-hung boilers have their own gas and air conditioning devices that limit their load adaptation range (usually 40% to 100%). When heating starts, ordinary wall-hung boilers have lower heating load requirements, while heating load requirements are greatest at the coldest time. . Therefore, it is difficult to choose a common wall-hung boiler product that can satisfy various load requirements and has a lower average operating cost.The condensing wall-hung boiler has handled the problem of load adaptability well, and its fully premixed structure and wide adjustment ratio range can better adapt to users and climate changes. The load range is generally 30% to 100%, and the minimum can be 20%. Obviously, condensing wall-hung boilers can provide floor heating users with a more energy-saving, more environmentally friendly, and more adaptable heat source to special circumstances.