What are the causes and hazards of low water level in heaters?

The hazards of the heater water level being too low or no water are: the water level is too low to submerge the hydrophobic inlet of the built-in hydrophobic cooling section, and steam will enter the hydrophobic cooling section, affecting the heat transfer process inside the hydrophobic cooling section. For those who need to rely on siphoning.

Vertical heaters and horizontal heaters with short-range full-channel hydrophobic cooling sections that function to maintain the normal flow of hydrophobic water, once the hydrophobic water level is lower than the population of the hydrophobic cooling section, the water seal.

If it is damaged, the role of the hydrophobic cooling section is lost, so that the heat contained in the hydrophobic can not be fully utilized, which affects the thermal economy. The hydrophobicity between the various stages of heater is generally connected in series by step. In the absence of water level, the steam in the primary heater with higher extraction pressure will enter the heater with lower extraction pressure in the next stage through the trap pipe, replacing the steam of some heaters with lower parameters, so that the overall thermal efficiency of the recuperation cycle is reduced.

For heaters with built-in hydrophobic cooling sections, when the water level is too low and the hydrophobic population is exposed to steam, a two-phase flow of steam and water is formed at the population, and the high-velocity flowing mixture will erode the pipe bundles, partitions and other components near the inlet of the hydrophobic cooling section. In the case of low water level, the hydrophobic cooling section does not work properly, and the hydrophobic subcooling discharged by the heater is subcooled.

Very small, the trap is susceptible to pressure loss during the flow process, causing the trap to flash in the pipe. After flashing, a high-speed flowing soda mixture is formed, which causes serious erosion damage to the elbows and valves in the pipeline. For systems with trap pumps, insufficient hydrophobic subcooling will also affect the NPSH of the trap.

adversely affected. The outlet temperature of the high-pressure heater is based on the reasonable feed water temperature. It is not possible to unilaterally pursue the higher the final feed water temperature, the more economical, because more steam extraction is used to increase the feed water temperature, steam turbine.

The heat consumption rate can be reduced, but the feed water temperature is too high, and the economizer.

The decrease in temperature difference leads to the increase in boiler exhaust gas temperature, resulting in a decrease in boiler efficiency and an increase in fuel consumption, which is generally uneconomical. <>

If the water level of the heater is too low, the suction inlet of the cooling section of the water will occasionally be exposed to the water surface, and the steam will enter the section, destroying the siphoning effect of the section, resulting in the change of the inlet end of the heater, and the heat loss of the steam will impact the U-shaped pipe of the cooling section, causing vibration, cavitation and other phenomena. The soda-water mixture flows into the next stage heater, which is squeezed out of the recuperation and extraction, further reducing the economy. If the water level of the heater is too high, part of the tube bundle will be submerged in water, reducing the heat exchange area and resulting in the degradation of heater performance.

It is very dangerous for the heater to run at high water levels, and if it is operated incorrectly or not treated in time, it can cause damage to the turbine body or system. The causes of high water level in the heater include the failure of the trap control valve, the hydrophobic pressure difference between adjacent heaters is too small, the turbine is overloaded, and the heater bundle is broken. <>

There are many reasons for the change of heater outlet temperature, specifically: heater vapor pressure change; load changes; changes in influent flow; inlet water temperature variation; Scaling on the vapor or water side of the heater; The air leakage of the low-pressure heater or the failure of the air in the high-pressure heater to be discharged in time will affect the heat transfer of the pipe wall; The hydrophobic water level is too high to reduce the heat transfer effect (heater hydrophobic adjustment); The internal steam distribution partition of the heater is not tight, which makes the steam short circuit; The heater water side partition is damaged, and the feed water is short-circuited; Leakage of heater water side bypass door; The exhaust backstop door is stuck and not fully opened, etc. The temperature of the heater outlet water is reduced, so that the operation economy of the unit decreases, such as the feed water heating every 10 decreases, the heat consumption rate will increase, the principle of using the steam extraction for the unit of the steam extraction and heat recovery system is to require as much as possible to be used in the steam turbine to do more work of low-pressure pumping, less for the higher the work of high-pressure pumping, generally require the higher the output temperature of the low-pressure heater, the better.

Main reasons: 1. Relaxation and leakage of steel pipe expansion port.

2. The steel pipe of the high-pressure heater is broken or broken.

3. The hydrophobic automatic adjustment door fails, and the door core is stuck or the pin is known to fall off the socks.

4. The water level gauge of the electric contact is out of order or displayed incorrectly.

A high-pressure heater is a device that uses part of the steam turbine to heat the feed water. As a kind of heat conversion device, it is mainly used in the heat recovery system of large thermal power units, and its heat transfer performance directly affects the economy and safety of the unit.

The steel pipe expansion mouth is loose and leaking.

The high-pressure heater steel pipe is broken or cracked.

The hydrophobic automatic adjustment door fails, and the door core jams or falls off.

The water level gauge at the electrical contact is out of order or displayed incorrectly.

Heater pipes are leaking. Trap pump failure. The heater trap is out of order. The load on the steam turbine is reduced.

The rise in temperature causes the water body to expand.