1. Comparison of boiler failure rates 1. Vacuum boiler The vacuum degree of the vacuum boiler is an important indicator of the stable and stable operation of the boiler. There are four main factors that often affect the vacuum degree:

1) Are there any leakage points in the boiler body, valves, and instruments? Currently, including imported valves and instruments, there is no guarantee that there will be no leakage within 3 years.

2) Whether the control part fails, it is inevitable that the boiler controller, negative pressure, and pressure controller will also fail during operation. For example, the failure rate of domestic controllers is higher.

3) Are the vacuum pump and three-way solenoid valve working properly? Since the vacuum pump and three-way solenoid valve do not operate frequently, the original imported ones are prone to jamming and malfunctioning during operation.

4) There should be no sudden change in load. Changes in boiler load are normal for boilers. Generally, boilers can meet the load regulation of 30%-100%.

The above failures will cause the vacuum degree of the boiler to change. At this time, you should check the air tightness of the boiler, whether the control part is normal, whether the vacuum pump and three-way solenoid valve are normal, check the load changes, and if they are normal, check the negative pressure and pressure controller. After the vacuum level is restored, the boiler can still be used normally. Otherwise, the boiler must be shut down for maintenance and comprehensive inspection. In actual operation, the fault repair rate of vacuum boilers is higher than that of pressure steam boilers, and the control requirements are higher than those of steam boilers.

2. The normal pressure boiler only has the basic time, temperature, and water level controls of the boiler. The hot water boiler controller is imported from abroad, and the failure rate is relatively low. There is no need to control equipment to maintain the vacuum degree, and there is no complicated control equipment. The personnel operation requirements are simpler than that of a vacuum boiler, and the chance of downtime for maintenance is less. In actual operation, the hot water boiler is much more stable.

2. Comparison of boiler safety

1. If the vacuum degree of the vacuum boiler cannot be guaranteed due to the above four factors, it may cause the boiler pressure to rise rapidly. The boiler body is a closed structure. If the operator is careless, it may still become a dangerous pressure steam boiler. The safer operation of vacuum boilers under negative pressure is based on the premise that there must be no problems with the boiler's vacuum.

2. Normal pressure boiler: Normal pressure hot water boiler is directly connected to the atmosphere. It is as simple as boiling water. Any failure will not cause pressure in the boiler. The boiler is safer and more reliable, and it is truly free of any danger.

3. Comparison of boiler thermal efficiency

1. The water volume of the vacuum boiler is small, and the primary water does not participate in the system circulation. The number of burner starts during operation is more than that of the normal pressure boiler, and the combustion thermal efficiency of the burner is low. On the premise that the vacuum degree is relatively stable, the thermal efficiency of the vacuum boiler can reach 91%. Changes in vacuum degree caused by unstable operation of ancillary equipment will also reduce thermal efficiency. The operating costs cannot be stable. As the service life of vacuum equipment and control components decreases, the failure rate increases and the thermal efficiency decreases.

2. The hot water volume of normal pressure boilers is larger than that of vacuum boilers. Primary water does not participate in the system circulation. The number of burner starts is less. The burner combustion thermal efficiency is high. The thermal efficiency of hot water boilers is also 91%. Moreover, the thermal efficiency of hot water boilers is stable during operation. There is no So many equipment failure rates are affected, and the structure is simple and durable.

4. Comparison of structural forms of internal heat exchangers

1. Vacuum boiler uses steam to exchange heat and has short preheating time. The boiler comes with a stainless steel "U" shaped tube heat exchanger. One end has a flange that can be opened for cleaning, but the other end cannot be opened and the heat exchanger cannot be completely cleaned.

2. Normal pressure boilers perform heat exchange through water-water, and the preheating time is longer than that of vacuum boilers. The boiler comes with a copper in-line tube heat exchanger with flanges on both ends for more thorough cleaning.

5. Comparison of service life of boiler bodies

1. Vacuum boilers Because vacuum boilers work under negative pressure, less primary water is replenished to reduce problems such as scaling and oxygen corrosion of the boiler body. Since the boiler body is sealed, the primary water cannot be dosed and maintained every year. Atmospheric pressure boilers also adopt internationally advanced anti-scaling methods. , Anti-oxygen corrosion measures, the actual boiler life is equivalent to that of an atmospheric pressure boiler. Even if the life of the boiler is longer, the service life of the boiler control components and burners cannot be longer than that of the atmospheric pressure boiler.

2. Atmospheric pressure boilers. Hot water boilers are equipped with soft water equipment to overcome the problem of boiler scaling. The indirect hot water boilers themselves have very little water replenishment. Sacrificial anodes are used for international protection to reduce oxygen corrosion. Boilers can be added with medicine every year for maintenance to slow down the corrosion of steel plates. Oxygen corrosion, and the external insulation of the boiler steel plate adopts a unique two-component insulation method, which is water-resistant, acid-resistant, alkali-resistant, oil-resistant, etc. Since the insulation material is glued to the boiler body, oxygen corrosion between the boiler steel plate and the air is eliminated, and the vacuum The boiler is insulated with glass wool, which cannot prevent oxygen corrosion between the steel plate and the air. Therefore, the service life of the hot water boiler is not shorter than that of the vacuum boiler. There is no basis for the 2 times life span difference.

6. Comparison of the production status of two types of boilers around the world

1. Vacuum boilers. Currently, only a few boiler factories in Japan, South Korea, and China produce vacuum boilers in the world. China's vacuum boilers have only begun to produce vacuum boilers after imitating Japan and South Korea in the past few years, and they are all newly established boiler factories. . Due to technical limitations in the actual operation of vacuum boilers, none of China's powerful famous brand boiler factories produce vacuum boilers. Famous companies such as Changsha Yuanda and Jiangsu Shuangliang (which has a boiler factory) that manufacture vacuum HVAC equipment in China also do not produce vacuum boilers. The world-famous European and American boiler manufacturers (such as Germany's Rolls, Boutrus, Viessmann, Spain's Lorca, Italy's Riello and Smith, the United States' Weimar, AB, etc.) do not produce vacuum boilers. Europe and the United States also do not produce vacuum boilers. Hardly used.

2. Atmospheric pressure boilers. Currently, hot water boilers are used in all countries around the world. All boiler factories in China and all European, American, Japanese, Korean and other countries produce hot water boilers, which have a history of nearly 100 years. There are thousands of boiler manufacturers in China that produce hot water boilers, and there are no more than ten manufacturers that produce vacuum boilers, and they are all newly established boiler factories. There are even fewer users, and they are only used in a few cities.

7. Comparison of boiler approval and annual inspection status

1. There is no need to declare to the boiler for installation and construction. The boiler body does not need annual inspection. Operators do not need employment certificates. The boiler occupies a small area and there are no specific requirements for the placement site.

2. There is no need to declare to the boiler for installation and construction. The boiler body does not need annual inspection. Operators do not need employment certificates. The boiler occupies a small area. There are no specific requirements for the placement site. The approval and annual inspection conditions are the same.