In various modern power distribution cabinets, the intelligent dehumidifier
What is condensation reason for substation switchgear?
Do you know the condensation reason for substation switchgear? This article will introduce the condensation reason from the Condensation definition, the Relationship between dew point temperature and ambient temperature and relative humidity, three condensation reasons for power switchgear, and two methods to solve condensation of substation switchgear.
Condensation is a process in which gas molecules slow down and clump together to form droplets or a liquid state when a gas is cooled and its temperature decreases. This usually occurs when a gas comes into contact with a surface that is cooler than its saturation temperature.
Equipment generates heat when operating, and the design and maintenance of cooling systems are critical to preventing equipment from overheating. Equipment such as substation switchgear, GIS switchgear, condensers, and radiators are used to control the temperature of electrical equipment to ensure it operates under rated operating conditions. Through condensation, the heat dissipation effect of the equipment is improved, thereby extending the life of the equipment and improving operating efficiency.
Relationship between dew point temperature and ambient temperature and relative humidity
Dew point temperature is the temperature that describes the saturation of water vapor in the air, and is also a representation of humidity parameters. There is a close relationship with ambient temperature and relative humidity, which are detailed below.
1. The relationship between relative humidity and dew point temperature:
Under the same ambient temperature, the higher the relative humidity, the higher the dew point temperature, and the dew point temperature is directly proportional to the relative humidity. This is because relative humidity describes the percentage of water vapor in the air, that is, the percentage of moisture the air contains relative to the maximum possible moisture at that temperature. High relative humidity means there is more water vapor in the air and therefore a correspondingly higher dew point temperature. This relationship shows that the degree of water saturation increases with increasing relative humidity.
2. Relationship between ambient temperature and dew point temperature:
Under the same relative humidity conditions, the higher the ambient temperature, the higher the dew point temperature, and the dew point temperature is directly proportional to the ambient temperature. This is because when the relative humidity remains constant, as the temperature increases, the air can hold more water vapor. Therefore, to keep the relative humidity constant, the dew point temperature also increases. This relationship reflects the fact that warmer air is able to hold more moisture. That is, when the relative humidity remains constant, as the temperature rises, the moisture content in the air increases.
Condensation Reason for substation switchgear
The main condensation reason for substation switchgear are in the following:
substation switchgear dew point temperature and ambient temperature
Explanation: The dew point temperature is the temperature at which the air is saturated. When the temperature in the air drops to equal to or lower than the dew point temperature, water vapor will condense into water droplets, forming condensation. The relationship between the internal temperature of the switch cabinet and the ambient temperature directly affects the content of water vapor in the air.
Influencing factors: When the temperature inside the switch cabinet is low, if the ambient humidity is high, it is easy to cause the dew point temperature to drop to a level similar to the ambient temperature, thus causing condensation. Therefore, in a high-humidity environment, controlling the temperature inside the switch cabinet to avoid too low dew point temperature is an important step to prevent condensation.
The influence of the installation position and number of substation switchgear dehumidifiers on condensation
Explanation: Reasonable setting of the position and number of dehumidifiers in the switch cabinet can effectively reduce the humidity in the air, thereby reducing the occurrence of condensation. A properly configured dehumidifier can provide enough heat inside the switch cabinet to keep the water vapor in the air at a relatively low level.
Influencing factors: The location of the dehumidifier should take into account the ventilation conditions inside the switch cabinet to ensure that moist air can fully contact the dehumidifier. In addition, the right number of dehumidifiers is also a key factor. Too many or too few dehumidifiers may lead to uneven distribution of humidity and increase the risk of condensation.
The impact of substation switchgear air conditioning mode on condensation
Explanation: The air conditioning system in the switch cabinet treats air differently in different modes. In cooling mode, the air conditioning system reduces the air temperature, while in heating mode, the system increases the air temperature. These two modes have a direct impact on the humidity and dew point temperature inside the switchgear.
Influencing factors: In humid environments, choosing the appropriate air conditioning mode is crucial. Cooling mode may cause the air temperature to drop, increasing the likelihood of condensation. The heating mode helps to increase the air temperature and prevent the dew point temperature from being too low, thereby reducing the occurrence of condensation. The correct selection of air conditioning mode can balance the relationship between temperature and humidity according to actual environmental requirements and reduce the risk of condensation.
How to Solve Condensation for substation switchgear?
Using enclosure heater or thermostat to solve condensation
Principle: The traditional method mainly heats the air inside the switch cabinet or the surface of the cabinet to increase the temperature and prevent the air temperature from falling below the dew point and causing condensation. The enclosure heater or thermostat is installed in the substation switchgear and automatically adjusts according to the ambient temperature and humidity conditions to keep the temperature in the cabinet within the set range.
Operation method: When the ambient humidity is high or the temperature is low, the heating element or thermostat starts to increase the internal temperature of the switch cabinet. Once the temperature returns to normal or the humidity drops, the heating device automatically stops.
Advantages: This method is simple and direct, and is suitable for condensation problems under general circumstances. However, it may consume some power.
Using Cabinet dehumidifier to solve condensation
Principle: The industrial cabinet dehumidifier in the cabinet reduces the humidity in the switch cabinet by absorbing moisture from the air, condensing water vapor and expelling the moisture out of the cabinet. This method mainly uses humidity control to ensure that the moisture in the air is maintained at a controllable level and prevents condensation from occurring.
Mode of operation: The enclosure dehumidifier is equipped with a humidity control function that automatically starts or stops to keep the humidity in the switch cabinet within the set range. It usually starts when the humidity exceeds a preset value, sucks in moist air, condenses the moisture, and then expels dry air out of the cabinet.
Advantages: Dehumidifiers can control humidity more finely, running only when needed, saving energy. It is suitable for scenarios with higher requirements for humidity control.
In conclusion, the enclosure dehumidifier is better than the enclosure heater or thermostat in the following aspects:
Energy Efficiency and Operational Complexity: Traditional methods of heating pads or thermostats are relatively simple, but can consume more power. In-cabinet dehumidifiers control humidity more precisely and only run when needed, making them more energy efficient.
Applicable scenarios: Traditional methods are suitable for condensation problems under normal circumstances, while cabinet dehumidifiers are suitable for scenarios with higher requirements for humidity control, such as in environments with dense electronic equipment and large humidity fluctuations.
Cost: In-cabinet dehumidifiers may have some additional costs in equipment and installation, but this may pay for itself in the long term through energy cost savings.
Due to the lack of understanding of a switchgear