What can go wrong with the water cycle of a gas steam generator?

Gas steam generator generally through the combustion of fuel to heat the water in the furnace output, supply life and heating. Under normal conditions, the horizontal water cycle is in a stable state, but when the cycle structure is not standardized or operating improperly, there are often some minor failures.

Down tube with steam:

Steam generator in normal operation, the drop tube is not allowed to exist in the steam, otherwise, the water needs to flow downward, the steam needs to float upward, the two relative to each other, both enhance the flow resistance, but also reduces the circulation flow, the situation is serious when the formation of gas resistance, prompting the water cycle to stop, resulting in a general lack of water in the water-cooled wall tubes and damage. In order to be able to solve this problem, the steam generator down tube can not be exposed to heat, should be connected to the water space in the cylinder, as far as possible, connected to the bottom of the cylinder, and to ensure that the drop tube inlet and the low water level of the cylinder between the height of not less than 4 times the diameter of the drop tube. To prevent steam from being carried into the tube.

Cycle stagnation:

In the process of steam generator use, the same cycle loop, when the parallel connection of each rising tube is not uniform when the heat, the heat of the weak tube of the density of the vapor mixture is necessarily greater than the heat of the strong tube to find that the density of the vapor mixture, in the descending tube of the water supply is more limited under the premise of the weak tube of the heat may be flow rate down, may be in a state of stopping, this situation is called cycle stagnation, when the rising tube of steam can not be carried in time. This situation is called circulation stagnation, at this time the steam in the tube can not be carried away in time, resulting in pipe wall overheating pipe rupture accident.

Vapor Stratification:

When the water-cooled wall tubes of the steam generator are arranged horizontally or reach a horizontal arrangement, and the flow rate of the vapor-water mixture inside the tubes is not too high, because the steam is much lighter than the water, the steam flows above the tubes and the water flows below the tubes, and this is called vapor stratification, and the tubes are easy to be overheated above the tubes due to the poor thermal conductivity of the steam and the damage. Therefore, the rising pipe or lead pipe of the vapor-water mixture cannot be arranged horizontally, and the inclination is usually not less than 15 degrees.

Circulation backflow:

When the parallel connection of each rising tube is very uneven heat, the heat of the strong tube of vapor mixture rising force, the flow rate is too large and the formation of the suction effect, resulting in the heat of the weak tube of vapor mixture and the normal direction of the cycle of the direction of the flow is different, this situation is known as the cycle of reflux. If the rising speed of the vapor bubble and the downward flow of water at the same rate, it will cause the bubble stagnation, the formation of "gas resistance", resulting in gas resistance section of the superheated pipe rupture.