Wuhan walk-in constant temperature and humidity room(Commonly used for environmental reliability testing of products in industries such as electronics, automobiles, and pharmaceuticals) To cope with the harsh climate of "high temperature and high humidity in summer (temperature exceeding 35 ℃, humidity exceeding 80%), and low temperature and dry in winter (temperature below 5 ℃, humidity below 40%)", its "precise temperature and humidity control" technology achieves a temperature control range of -40 ℃~80 ℃ (accuracy ± 0.5 ℃) and a humidity control range of 20%~95% RH (accuracy ± 3% RH) through "dynamic adjustment system+regional adaptation design+precision calibration mechanism", meeting the requirements of high demand testing scenarios.

　　1、 Core temperature control system: layered regulation to cope with climate fluctuations in Wuhan

In response to the large temperature difference between winter and summer in Wuhan, the temperature control system adopts a "multi-stage heating+intelligent cooling" layered adjustment to avoid sudden temperature rises and drops:

Heating system: Gradient heating and anti overshoot: equipped with stainless steel finned heaters (power divided into 3 levels: 10kW, 20kW, 30kW), combined with the low-temperature characteristics of Wuhan in winter. When starting at low temperatures (such as from 5 ℃ to 25 ℃), the 10kW low-power heating is first turned on, and when the temperature approaches the target value (± 2 ℃), it switches to 5kW fine-tuning. The heating rate is controlled by PID algorithm (≤ 2 ℃/min) to avoid temperature overshoot caused by traditional single-stage heating (overshoot decreases from ± 2 ℃ to ± 0.3 ℃); The heater is equipped with a built-in temperature fuse (with a melting temperature of 90 ℃) to prevent equipment damage caused by high temperature combined with heating in Wuhan's summer environment.

Refrigeration system: Double stage compression and high temperature resistance: Adopting a double stage screw compressor (with a 40% increase in refrigeration efficiency compared to single-stage compression), it is suitable for Wuhan summer temperatures above 35 ℃. Under high temperature conditions (such as indoor temperature control of 60 ℃), the temperature of the refrigerant (R410A) is reduced to 15 ℃ through the first stage compression, and further reduced to -10 ℃ through the second stage compression to ensure stable refrigeration capacity; The condenser adopts a dual mode of air cooling and water cooling. During high temperatures in summer, it automatically switches to water cooling (the cooling water comes from Wuhan municipal water supply, with a temperature ≤ 28 ℃), which improves the heat dissipation efficiency by 30% and avoids the problem of insufficient cooling by air cooling in high temperature environments.

　　2、 Precise humidity control system: dynamic balance to solve the extreme dry and wet values in Wuhan

For extreme high and low humidity scenarios in Wuhan, the humidity control system ensures humidity accuracy through dynamic balance of "dehumidification+humidification":

Dehumidification System: Multi mode adaptation to high humidity: Adopting a dual mode of "freezing dehumidification+rotary dehumidification", during the rainy season in Wuhan (humidity exceeding 80%), the dew point of the air is first reduced to 5 ℃ through freezing dehumidification (removing a large amount of moisture), and then the humidity is reduced to the target value (such as 50% RH) through rotary dehumidification (silicone rotary wheel, moisture absorption capacity ≥ 1.5kg/kg dry air), which improves the efficiency by 50% compared to single freezing dehumidification and avoids frost formation in low-temperature environments; The dehumidification system is equipped with a humidity sensor (accuracy ± 2% RH) to monitor humidity changes in real time. When the outdoor humidity in Wuhan exceeds 90% in summer, the dehumidification power is automatically increased to prevent high humidity outdoor air from infiltrating and causing indoor humidity fluctuations.

Humidification System: Steam Humidification to Prevent Low Humidity: An electrode type steam humidifier (adjustable humidification capacity from 0 to 5kg/h) is used to adapt to the dry environment of Wuhan in winter (indoor target humidity of 40% RH). The humidification capacity is controlled by PLC to avoid uneven humidity caused by traditional ultrasonic humidification (indoor humidity deviation is reduced from ± 5% RH to ± 2% RH); Install an ion exchange resin filter at the inlet of the humidifier to remove calcium and magnesium ions from Wuhan tap water, prevent scale from blocking the humidification electrode, and extend the equipment's lifespan (from 6 months to 12 months); Real time monitoring of water temperature during humidification process (controlled at 80-90 ℃) to ensure steam purity and avoid impurities affecting test products (such as electronic components).

　　3、 Regional adaptation and precision assurance: optimization tailored to the usage scenarios in Wuhan

Optimization of airflow organization: To address the uniformity of large spaces, a walk-in constant temperature chamber (common size 5m × 4m × 3m) adopts an upward supply and downward airflow organization, with a diffuser installed at the top (adjustable wind speed of 0.5-1m/s). During high temperature testing in Wuhan in summer (such as indoor temperature of 70 ℃), the wind speed is increased to 1m/s to accelerate hot air circulation and avoid indoor temperature differences (reduced from ± 1 ℃ to ± 0.5 ℃); Install a filter screen (with a filtration accuracy of 5 μ m) at the return air outlet to filter dust in the air of Wuhan (especially during spring and autumn sandstorms), preventing dust from blocking the heat exchanger and affecting the accuracy of temperature and humidity control.

Insulation and sealing design: resistant to environmental interference in Wuhan: The wall is made of double-layer color steel plates (filled with a 100mm thick polyurethane insulation layer in the middle, with a thermal conductivity of ≤ 0.024W/(m · K)), which saves 30% energy compared to traditional single-layer insulation. It can effectively isolate outdoor low temperatures (such as -2 ℃) in Wuhan in winter, avoiding indoor heat loss; The door opening adopts double sealing strips (EPDM rubber with temperature resistance of -50 ℃~80 ℃), combined with an automatic inflation sealing device, which can prevent high humidity outdoor air from infiltrating during the rainy season in Wuhan (reducing infiltration by 90%), ensuring stable indoor humidity.

Regular calibration mechanism: Maintain long-term accuracy: Use a standard temperature and humidity recorder (accuracy ± 0.2 ℃, ± 1% RH) to calibrate indoor temperature and humidity every month. Increase the calibration frequency (once every two weeks) during seasonal changes in Wuhan (such as April and October, with large temperature differences); Invite third-party testing institutions (such as Wuhan Institute of Metrology and Testing) to conduct accuracy testing every year to ensure compliance with the requirements of GB/T 2423.1-2008 standard; Adjust the temperature control and humidity parameters based on calibration data (such as reducing the start stop temperature difference of the refrigeration system appropriately during high temperatures in summer) to maintain long-term accuracy of the equipment.

The "precise temperature and humidity control" technology of Wuhan's walk-in constant temperature and humidity chamber solves the control problem in harsh temperature and humidity environments through customized design for local climate, providing stable environmental testing conditions for enterprises in Wuhan and surrounding areas. In the future, AI algorithms can also be integrated to automatically optimize temperature and humidity control strategies by learning historical climate data from Wuhan, further improving accuracy and energy-saving effects.