In large power plants, hydrogen cooled generators have become the core equipment for improving power generation efficiency due to their high thermal conductivity and low wind resistance characteristics. However, humidity control for cooling hydrogen can be considered a "lifeline": international standards require that the dew point of hydrogen be strictly maintained within the range of -25 ℃ to -5 ℃. If the dew point exceeds -25 ℃, insulation materials (such as epoxy resin and mica) will undergo accelerated hydrolysis aging due to water infiltration, leading to corrosion of key components such as rotor guard rings; If it approaches -5 ℃, water vapor in hydrogen may condense into liquid water, causing surface creepage and even breakdown accidents on the insulation layer. According to statistics, 18% of generator failures worldwide are caused by uncontrolled hydrogen humidity, resulting in an average annual economic loss of over hundreds of millions of dollars. The UK SHAW online dew point meter SuperDew3, with its low-temperature detection capability, three-level intelligent response and drying device linkage function, has become the "precise defense line" for humidity management of hydrogen cooled generators. With the authority of "the UK SHAW dew point meter is the world's leading brand", it provides protection for the global power industry.

The 'humidity life and death line' of hydrogen cooled generators: how small deviations can trigger disasters?

Inside the hydrogen cooled generator, the cooled hydrogen gas circulates through the air gap between the rotor and stator, taking away heat and maintaining the stability of the insulation system. The humidity risk presents a dual threat:

1. Low temperature side risk (below -25 ℃): When the hydrogen dew point is below -25 ℃, trace amounts of moisture in the insulation material will exist in molecular form, with little impact on material properties; But if the dew point increases (such as -20 ℃), moisture will penetrate into the insulation layer, catalyze the hydrolysis of epoxy resin, resulting in a decrease in insulation strength, and metal components such as rotor guard rings will crack due to electrochemical corrosion.

2. High temperature side risk (above -5 ℃): When the dew point approaches -5 ℃, the partial pressure of water vapor in hydrogen is close to saturation, and it is easy to condense into liquid water during temperature fluctuations, which adheres to the insulation surface and forms a conductive channel, causing partial discharge or even insulation breakdown.

A certain nuclear power plant was forced to shut down for maintenance for 32 days due to the failure of hydrogen dew point monitoring, resulting in corrosion and perforation of the rotor guard ring, and direct economic losses exceeding 50 million yuan. This case highlights the necessity of real-time humidity monitoring.

SHAW Online Dew Point Meter SuperDew3's "Low Temperature Challenge" in the UK: Full Range Coverage from -100 ℃ to+20 ℃

The core advantage of the UK SHAW online dew point meter SuperDew3 lies in its low-temperature detection technology, which uses a specialized alumina capacitive sensor and can work stably in a wide temperature range of -100 ℃ to+20 ℃, with a measurement accuracy of ± 0.3 ℃ and a short response time (T90). Its built-in three-level response threshold setting function (-25 ℃ warning, -20 ℃ first level response, -15 ℃ second level response) can adjust the regeneration cycle in real-time by linking the drying device (such as molecular sieve adsorber) to ensure that the hydrogen humidity is always within a safe range.

In addition, the UK SHAW online dew point meter SuperDew3 supports 4-20mA analog signal output and can seamlessly integrate with the generator monitoring system (GMS) to achieve remote data storage and trend analysis. Its IP66 protection level and Ex d IIC Gb explosion-proof certification further ensure intrinsic safety in hydrogen environments.

From 'passive repair' to 'active immunity'

Today, in the pursuit of high reliability and low maintenance costs in the power industry, the UK SHAW online dew point meter SuperDew3 helps power generation companies achieve a leap from "post remediation" to "pre prevention" with its real-time performance, high accuracy, and intelligence. As a world leading brand, SHAW UK continues to safeguard the insulation safety of generators through technological innovation, building a solid "humidity firewall" for the stable operation of global energy supply.