The full name of vacuum boiler is called vacuum phase change boiler. Notice two nouns, one is vacuum, the other is phase transition. Vacuum boiler is a vacuum environment in which negative pressure is formed in a closed furnace. It fills the body with heat medium water, heats the heat medium water through combustion or other methods, evaporates and condenses the heat medium water to the heat exchanger, and then heats the water heated by the heat exchanger.

Operating principle:

Vacuum boiler forms a negative pressure vacuum environment inside the closed furnace body, and fills the body with heat medium water. The heat medium water is heated by combustion or other means. The heat medium water is heated to generate steam. The steam heats the water in the heat exchanger tube through condensation heat exchange to realize the supply of hot water.

Heat conversion diagram of vacuum boiler:

Oil, natural gas, gas, electricity -- > combustion (electric conversion heat) -- heat medium water -- > steam condensation heat exchange after boiling -- > heat exchanger -- > heat conduction -- > water

Working principle of vacuum boiler: using the low boiling point of water under low pressure, quickly heat the heat medium water filled in the sealed furnace to make the heat medium water boil and evaporate high-temperature steam. The steam condenses on the heat exchange pipe to heat the cold water in the heat exchange pipe, so as to achieve the purpose of supplying hot water.

Standard sea level atmospheric pressure: 1.013 × 105pa=101.3kpa, and the boiling point of water is 100 ℃; The higher the altitude, the lower the atmospheric pressure and the lower the boiling point:

Qinghai Tibet Plateau: the average altitude is 4000m, the atmospheric pressure is 62kpa, and the boiling point of water is 87 ℃;

Mount Qomolangma: altitude up to 8848m, atmospheric pressure 33kpa, boiling point 71 ℃;

The vacuum boiler forms a low-pressure environment with almost no air by vacuuming, and then uses water to boil at low pressure (below atmospheric pressure) to produce

Steam generation works on the principle of heat output through steam water condensation and heat exchange.

Corresponding table of boiling point and vacuum degree of water:

Vacuum degree (kPa) 0 - thirty-one - fifty-four - seventy - eighty-one - eighty-nine - ninety-four - ninety-seven - ninety-nine - one hundred and one

Boiling point of water (℃) one hundred ninety eighty seventy sixty fifty forty thirty twenty 0

The normal working temperature of vacuum boiler is lower than 90 ℃, and the vacuum degree is lower than -30kpa.

The heat medium water in the vacuum boiler is high-purity water that has undergone special treatment such as deoxidization and descaling. It is filled at one time before leaving the factory. When it is used, it is closed and circulated inside the unit (vaporization → condensation → vaporization), without increase or decrease. It does not need to be supplemented or replaced within the service life of the unit.

Therefore, the inside of the vacuum boiler body will not scale or corrode, and the normal service life can reach more than 20 years, far exceeding the service life of the ordinary hot water boiler of about 10 years.