We need a heating boiler for heating in the winter. There are two types of boilers for domestic heating: hot water boilers and steam boilers. A hot water boiler is a boiler that generates hot water, and a steam boiler is a boiler that generates steam.
In actual heating applications, hot water boilers are generally used for heating. Because most of the ends such as radiators, fan coils, and floor heating are heated by hot water, even if a steam boiler is used, the board is generally used to exchange steam into hot water. The replacement of steam with hot water adds a heat exchange link, which increases the heat exchange loss. At the same time, the use of steam boilers for heating has the following disadvantages: 1. The temperature of the heat exchanger changes too quickly, and it is easy to cause water leakage from the heat exchanger. 2. The pressure change of the heat exchanger is large and easy to burst. 3. The surface temperature of the radiator is high and it is easy to be burned. 4. Poor heating effect will cause water hammer and water hammer, which will cause noise and damage radiators and pipes. 5. The thermal efficiency is not high.
In the "Code for Heating Ventilation and Air Conditioning of Civil Buildings" (GB50736-2012) issued in 2012, corresponding provisions were made on whether heating boilers should use hot water boilers or steam boilers: 8.11.10 In addition to kitchens, laundry, high temperature In addition to the heat load of steam, which must be used for disinfection and winter air-conditioning humidification, the remaining heat load should use a hot water boiler as the heat source. When the ratio of the steam heat load to the total heat load is greater than 70% and the total heat load is ≦ 1.4MW, a steam boiler can be used.
Compared with steam, the advantages of hot water as a heating medium have already been proven in practice, so the idea of using water as a heating medium for boilers as much as possible is emphasized. However, when the proportion of steam heat load is large and the total heat load is not very large, the steam heating and hot water heating systems are divided. The system is often complicated, the investment is high, and the boiler selection is difficult, but the energy saving effect is limited. Uniform heating medium is often more economically and technically reasonable.
Therefore, in addition to some special circumstances when heating, we should try to use hot water boilers for heating.