The economizer is a heating surface, which uses low-temperature flue gas to heat the water supply. The boiler feed water in the tail flue of gas boiler is heated to the heating surface of saturated water under the pressure of drum. Due to the absorption of relatively low temperature flue gas, the exhaust temperature of flue gas is reduced, energy is saved and efficiency is improved. It is called energy saver.

燃?xì)忮仩t的分類方法有很多種，可分為以下幾種：根據(jù)給水加熱的程度，可分為非沸騰型和沸騰型。

There are many kinds of classification methods of gas-fired boiler, which can be divided into the following: according to the degree of feed water heating, it can be divided into non boiling type and boiling type.

根據(jù)制造材料：有兩種鑄鐵和鋼管節(jié)能器。非沸騰型節(jié)能器主要由鑄鐵制成，但它們也由鋼管制成，而沸騰型節(jié)能器只能由鋼管制成。鑄鐵節(jié)能器主要用于壓力≤2.5MPa的鍋爐。如果壓力超過2.5MPa，則應(yīng)使用由鋼管制成的省煤器。

According to the manufacturing materials: there are two kinds of cast iron and steel tube economizers. Non boiling economizers are mainly made of cast iron, but they are also made of steel pipes, while boiling economizers can only be made of steel pipes. Cast iron economizer is mainly used for boilers with pressure ≤ 2.5MPa. If the pressure exceeds 2.5MPa, economizer made of steel pipe shall be used.

根據(jù)設(shè)備的形式：有兩種類型的垂直和水平。根據(jù)排氣和給水的相對流向：有三種類型：下游，逆流和混合。

According to the form of equipment: there are two types of vertical and horizontal. According to the relative flow direction of exhaust and feed water, there are three types: downstream, countercurrent and mixing.

回收：在燃?xì)忮仩t（汽包鍋爐）啟動過程中，沒有建立蒸汽 - 水管道的循環(huán)，即鍋爐給水處于停滯狀態(tài)，省煤器中的水處于停電狀態(tài)。一個(gè)不流動的狀態(tài)，鍋爐燃燒。由于煙氣溫度的升高，省煤器中的水很容易蒸發(fā)，使節(jié)能器部分過熱。為了避免這種情況，來自汽包的濃縮水管的管道連接到管道以節(jié)省能量。該裝置的入口，作為再循環(huán)管，使節(jié)能器中的水保持流動狀態(tài)。避免蒸發(fā)。

Recovery: during the start-up of gas boiler (drum boiler), there is no steam water pipeline circulation, that is, the boiler feed water is in a standstill state, and the water in the economizer is in a power failure state. In a non flowing state, the boiler burns. Due to the increase of flue gas temperature, the water in economizer is easy to evaporate, which makes the economizer part overheat. In order to avoid this situation, the pipeline from the concentrated water pipe of the drum is connected to the pipeline to save energy. The inlet of the device acts as a recycling pipe to keep the water in the economizer flowing. Avoid evaporation.