Current situation and development prospect of the

Current situation and development prospect of atmospheric hot water boiler and its heating system

classification number: tk229 document identification code: a

article number: (2000) the present situation of atmospheric pressure hot water

boiler and its heat supply system and their developmentyue zhong

(Capital Economic Trade University, Beijing 100026, China) Abstract：The paper analysised the present situation and problems of atmospheric pressure hot water boiler and its heat-supply system,look forward their prospects.

Key words：Hot water boiler; Heat Supply system; Summarize ▲ 1 development of atmospheric hot water boiler and its heating system in the 1970s, China began to apply atmospheric hot water boiler to the heating system. In 1971, Liaoning Province, this was due to the decline of its thermal expansion. Lingyuan District of Liaoning Province transformed the original pressure hot water boiler heating system into an atmospheric hot water boiler heating system (as shown in Figure 1), changing the boiler from a closed form to an open form, ensuring that the boiler is always connected with the atmosphere during its operation and is dissatisfied with water. The circulating water pump originally set at the return side of the boiler is changed to the outlet side of the boiler. There is no high-level water tank in the system, and the radiator adopts the way of bottom in and top out. This system is a single point constant pressure atmospheric hot water boiler heating system. Its radiator and rigid PVC foamed plastic are widely used as "future materials" in construction, decoration, furniture, advertising and other fields. The heating pipeline is under pressure, but the boiler is not under pressure, commonly known as the "reverse pull" heating system, The resistance regulating valve on the return water pipeline of the system plays the role of regulating and reducing the return water pressure to ensure that the boiler inlet pressure is normal pressure. Figure 1 Schematic diagram of atmospheric hot water boiler heating system 1 Atmospheric hot water boiler 2 Radiator 3 In 1982, the hydrostatic hot water boiler heating system appeared in Dalian (as shown in Figure 2). The boiler does not bear the pressure provided by the water pump, but only the static pressure of the water column below the water level of the water tank. The pressure of the boiler is related to the height of the system. The pressure provided by the water pump is used to overcome the flow resistance of the heating system. The direct large gas pipe is high and thin, which cannot guarantee the boiler opening. From the perspective of safety, the atmospheric hot water boiler that only bears the static pressure of water in the boiler is superior. Figure 2 Schematic diagram of static pressure hot water boiler heating system 1 Static pressure hot water boiler 2 Radiator 3 High level water tank 4 Circulating water pump in 1985, Lushun boiler plant developed a two-point constant pressure and atmospheric pressure hot water boiler heating system (as shown in Figure 3). The radiator is placed in the downstream pipeline, and the heat transfer conditions are significantly improved. However, the open and close valve technology fails to pass the test, which brings great trouble to the system

in the next few years, many departments have done some work in developing the opening and closing of atmospheric hot water boiler heating system. In recent years, the atmospheric hot water boiler heating system has developed to high-rise buildings, and there has been an atmospheric hot water boiler heating system for heating 21 storey buildings

in foreign countries, atmospheric hot water boilers have also developed greatly. Atmospheric hot water boilers have appeared in Japan, and there are no reports about atmospheric hot water boilers used in heating systems in Europe and the United States, but they are concerned about the development of China and Japan. Figure 3 Schematic diagram of heating system of double point constant pressure and atmospheric pressure hot water boiler 1 Circulating water pump 2 Boiler 3 Resistance regulating valve 4 Open and close valve 5 Radiator 6 Advantages of high-level water tank

2 atmospheric hot water boiler the author investigated the design, manufacture, installation, use, management and supervision of atmospheric hot water boilers in Beijing, Qingdao, Jinan, Dalian and other places. The development of atmospheric hot water boilers has the following outstanding advantages:

(1) boilers are relatively safe

the boiler is connected with the atmosphere, which eliminates the possibility of explosion to a certain extent

(2) save high-quality steel and simplify the manufacturing process

the pressure parts of atmospheric hot water boilers are reduced, and the use of high-quality steel for manufacturing pressure parts of boilers is reduced. The supply of high-quality boiler steel in China has been very tight, and the use of atmospheric hot water boilers is very meaningful in this regard. The atmospheric hot water boiler can be free from flaw detection, and fillet welded flat plate structure can be used in some parts, which simplifies the process to a certain extent

(3) simplify the management of atmospheric hot water boiler

because the atmospheric hot water boiler is relatively safe, the management of the use, design, manufacture and installation of the atmospheric hot water boiler is relatively simplified, and the requirements for the boiler room are also reduced

(4) the scrapped boiler can be reused

this is a very important reason for the existence and development of atmospheric hot water boilers. According to statistics, the service life of industrial boilers in China is very short. A large number of boilers are scrapped prematurely every year. If the waste is used and converted into atmospheric hot water boilers, the boilers will continue to be used for many years, saving a lot of human, material and financial resources

(5) low price

due to the simplified manufacturing process, less steel consumption, low material quality and obvious cost, our customers have decreased widely

(6) in the heating system of buildings with about three floors below, the operation cost of pressure hot water boiler is equivalent to that of atmospheric hot water boiler. 3 problems existing in the production and development of atmospheric hot water boiler the production and use scale of atmospheric hot water boiler has developed extremely rapidly, but its technical level has developed slowly, the design, manufacture, installation and use are in an anarchic state, the management and supervision are insufficient, and accidents continue to occur, which are embodied in the following aspects:

(1) the atmospheric hot water boiler manufacturing plant has developed rapidly, the layout is unreasonable, and the production is blind. According to estimates of relevant departments, there are more than 1000 atmospheric hot water boiler manufacturers in China