There are many types of boilers. According to the output status, they can be divided into hot water boilers and steam boilers. The working fluid of the steam boiler is water, and the output working fluid is steam. The working fluid of the hot water boiler is water, and the output working fluid is unsaturated hot water. These two types of boilers seem to be similar, but in fact they are quite different. They have different application ranges and fields, and each has its own advantages.
The hot water boiler uses hot water as the heat medium, the temperature is low, and the temperature difference with the flue gas is relatively large, and the boiler exhaust gas temperature is relatively low, so the efficiency of the boiler is relatively high. The specific heat capacity of water is large, the hot water capacity in the system is large, and the heat storage capacity is strong. When the thermal operating condition or the hydraulic operating condition fails in a short period of time, it will not obviously cause large fluctuations in the heating condition. The hot water heating system can be pumped for long-distance transportation, with small heat loss and large heating radius, which can meet the requirements of urban central heating planning. Therefore, hot water as a heat medium is suitable for air conditioners, heaters, low temperature ovens, drying equipment, hot water tanks for textile printing and dyeing, and various low temperature heating, air conditioning coils and heat exchange equipment.
The current boilers in my country are mainly steam boilers. Using steam as a heat medium has low cost and wide adaptability, and can simultaneously meet the heat requirements of a variety of users who have different requirements for pressure and temperature. The second is that the steam is non-toxic, can directly heat food, etc., even if there is a leakage, it will not harm the environment and is safer. The steam temperature is higher and the latent heat of vaporization is large. Compared with the hot water, it can reduce the heat exchange area of the equipment and reduce the cost, and the thermal inertia is small.