According to the humidification method, it is basically divided into steam humidification and water mist humidification.

Steam Humidification:

Generally speaking, water vapor in steam humidification engineering belongs to high-temperature steam, which is slightly higher than the latent heat of gaseous water at room temperature. So after the air is humidified by steam, the latent heat will slightly increase, so the dry bulb temperature of the space will increase by 1-2 ℃. Due to the limited increase in dry bulb temperature of air, steam humidification is also known as isothermal humidification.

After the liquid water in the steam generator is heated and vaporized into saturated water vapor, the water vapor is directly distributed in the air conditioning box or duct through the steam distributor. Then, the water vapor is completely mixed with air and the air is absorbed to achieve humidification, which increases the moisture content of the air.

1. Generators: Available in various types

① Steam boiler humidification system

Use electric heating, fuel oil, or gas as the heating source. Heat liquid water to 1-10kg/CM ² After saturation with water vapor at pressure G, the steam is depressurized to 7-25PSI through a pressure reducing station, and then evenly distributed by a distributor in the air conditioning box or duct for air humidification.

② Liquid/steam heat exchange steam humidification system

Using high-temperature liquid (hot water) or industrial grade steam, pure water (RO/DI) is heated and evaporated into clean steam through heat exchange, and then evenly distributed by a distributor in the air conditioning box or duct for air humidification. In order to prevent the generation of impure substances in steam boilers from polluting steam quality and affecting the cleanliness level of air conditioning, the existing high-temperature steam or hot water can be used to generate low-pressure secondary pure steam as air conditioning humidification by passing through tube or plate type heat exchangers. This type of system is more suitable for situations where high-pressure steam boilers, high-temperature hot water boilers, or high-temperature waste heat recovery are already installed or required, otherwise it will form a dual investment.

③ Electric steam humidification system

After heating pure water with the heat generated by electrification using a resistor to generate water vapor, the steam is then distributed by a distributor in the air conditioning box or duct for air humidification.

④ Electrode type steam humidification system

Insert an electrode plate into the water, heat the water and evaporate it into steam using the heat generated by the movement of ions in the water after being electrified, and then distribute the steam in the air conditioning box or duct through a distributor for air humidification.

2. Rapid absorption steam diffusion device:

Explore how to provide 100% dry saturated steam at low pressure and how to mix with air in the most efficient and uniform manner, and be absorbed in the shortest time and distance. When steam encounters cold air, it immediately releases heat and becomes condensed water, so steam humidification engineering aims to spray saturated dry steam instead of a mixture of steam and water. It is very important to provide dry saturated steam and distribute it evenly. The methods include:

① High efficiency steam water separator

② Long plastic steel nozzle

③ , jacket type single tube steam humidification distributor

④ Multiple nozzle design

Water Mist Humidification:

Mainly, small particles of water droplets atomized by nozzles or ultrasonic oscillators are distributed in air conditioning boxes or ducts and mixed with air. This small water droplet will absorb the sensible heat of air through heat exchange and convert it into the latent heat of evaporation of water (approximately 584.3kcal/kg Dry Air at 23 ℃). Finally, the small water droplet will replace it with gaseous water as one of the components of the air, and the dry bulb temperature of the air will significantly decrease.

In the process of water mist humidification, the latent heat of water vaporization comes from the sensible heat of air, and the enthalpy of liquid water at room temperature is relatively small compared to the enthalpy of gaseous water. The total enthalpy of air remains almost unchanged after water mist humidification. So the enthalpy of liquid water vaporization does not contribute much to the increase in the total enthalpy of air; Therefore, water mist humidification is also known as isoenthalpy humidification.

If the room temperature is at high temperature and low humidity, such as in desert areas, water mist humidification method can be used to increase air humidity and reduce air temperature, which has the advantage of saving energy; But if the room temperature is at low temperature and low humidity, such as in winter, it is necessary to preheat the air first, significantly increase the dry bulb temperature of the air, and then increase the heat enthalpy of the air, in order to achieve the goal of air humidification through water mist humidification and achieve the optimal moisture content of the air. Due to the low air temperature, its heat transfer efficiency is poor, and the vaporization time and absorption distance of water droplets become longer. If there is not enough enthalpy, the water droplets will become larger and larger, resulting in condensation. Therefore, when using water mist humidification, it is necessary to pay attention to whether there is enough enthalpy provided and absorption distance. In winter, if there is no appropriate source of waste heat and it is necessary to rely on electric heating to increase temperature (enthalpy), it will not only fail to save energy, but also waste energy even more. So when applying, it is necessary to consider this issue and related costs more.

① Is the absorption distance long enough.

② Is the size of water droplet particles and nozzle distribution configuration appropriate.

③ Can the humidification amount be proportionally controlled.

Proportional output control is a test for water mist humidification. Generally, manufacturers claim to accept proportional control signals of 4-20MA or 2-10V. However, after in-depth understanding of its structural design, it is found that its humidification output is not proportional, but ON-OFF control. Due to the fact that the ON-OFF control method cannot meet the requirements of modern precision air conditioning control (which is very important), when encountering instruments or equipment that can accept proportional signals and claim to be capable of proportional output power, whether it is steam humidification or water mist humidification, it is necessary to carefully understand to avoid being misled.

Note: Absorption distance: The absorption distance referred to as steam humidification is the distance from the nozzle to the first obstruction without condensation; The absorption distance referred to as water mist humidification is the distance from the nozzle to the water removal plate or the first obstruction that can provide the designed outlet humidity.