Reasons for the Slow Temperature Drop in Constant Temperature and Humidity Laboratories and Their Solutions
2024.12.16
In numerous fields such as scientific research and industrial production, constant temperature and humidity laboratories play a vital role, providing precise and stable temperature and humidity environments for experiments. However, sometimes the problem of slow temperature drop in the laboratory may occur, which will not only affect the progress of experiments but also potentially interfere with the experimental results. Today, Guangzhou Cleanroom Construction Co., Ltd. will analyze the reasons for this problem in depth and offer effective solutions.
I. Reason Analysis
1. Refrigeration System Malfunctions
· Refrigerant Leakage: This is one of the common reasons for poor refrigeration effects. Over time or due to the aging of equipment components, tiny cracks may appear in the refrigeration pipes, causing the refrigerant to gradually leak. Insufficient refrigerant will significantly reduce the refrigeration capacity, resulting in a slow temperature drop. For example, in some old laboratory equipment, refrigerant leakage often occurs due to long-term operation and a lack of regular maintenance.
· Reduced Compressor Efficiency: The compressor is a core component of the refrigeration system. If it is severely worn or malfunctioning, the suction and discharge pressures will be abnormal, the compression ratio will decrease, and the refrigeration ability will be weakened. Just as a decline in a car engine's performance will affect its speed, a reduction in the compressor's efficiency will directly affect the cooling speed of the laboratory.
2. Poor Ventilation and Airflow
· Duct Blockage: If the air ducts inside the laboratory are not cleaned for a long time, dust, debris, and other substances will accumulate in them, impeding the air circulation. Just as blocked blood vessels in the human body will affect blood circulation, blocked air ducts will hinder the exchange of hot and cold air, resulting in uneven temperature distribution and a slow temperature drop. This problem is particularly prominent in some laboratories in harsh environments, such as those close to factory workshops or in areas with a lot of dust.
· Fan Malfunctions: Fans are responsible for driving the air to circulate in the laboratory. If the motor of the fan is damaged, the blades are deformed, or the rotation speed is abnormal, the amount of air circulation will be insufficient, and the cooling capacity cannot be effectively transferred to every corner, thus causing a slow temperature drop. For example, in some high-humidity environments, the motor of the fan may be damaged due to moisture, affecting its normal operation.
3. Excessive Heat Load
· High Heat Generation of Equipment: If there are a large number of heat-generating equipment in the laboratory, such as electronic instruments and high-power lamps, and the heat generated during the operation of these equipment exceeds the load capacity of the laboratory's refrigeration system, it will be difficult for the temperature to drop rapidly. For example, in some electronic chip research and development laboratories, many high-precision testing equipment operate simultaneously, releasing a large amount of heat and posing a great challenge to the constant temperature and humidity environment.
· Frequent Personnel Activities: Personnel are also a non-negligible heat source. When there are many people in the laboratory and they enter and leave frequently, the heat emitted by the human body and the hot air brought in from the outside will increase the heat load of the laboratory. Especially in some small laboratories with a relatively high personnel density, the impact of this increased heat load on the temperature is more obvious.
4. Control System Problems
· Temperature Sensor Malfunctions: Temperature sensors are responsible for real-time monitoring of the laboratory's temperature and sending signals back to the control system to adjust the refrigeration capacity. If the sensors have deviations or are damaged, the control system will receive incorrect temperature information, making it unable to accurately start or adjust the refrigeration system, resulting in abnormal temperature drops. For example, if the sensors are bumped or their accuracy decreases after long-term use, this problem will occur.
· Improper Control System Parameter Settings: Even if the refrigeration system and other hardware equipment are normal, if the parameters such as the temperature set value and the refrigeration start-stop temperature difference in the control system are not set reasonably, the cooling speed and effect of the laboratory will be affected. For example, if the refrigeration start-stop temperature difference is set too large, the refrigeration system will not start in a timely manner, causing a slow temperature drop.
II. Solutions
1. Refrigeration System Maintenance and Repair
· Refrigerant Replenishment and Leak Detection: Regularly conduct pressure tests on the refrigeration system to check for refrigerant leakage. Once a leakage point is found, it should be repaired promptly, and an appropriate amount of refrigerant should be replenished according to the equipment requirements. At the same time, it is necessary to ensure that the quality of the refrigerant meets the standards to avoid affecting the refrigeration effect due to impure refrigerant.
· Compressor Maintenance and Replacement: Regularly check the operating status of the compressor, including parameters such as suction and discharge pressures, temperature, and vibration. For compressors that are severely worn or malfunctioning, they should be replaced or professionally repaired in a timely manner to ensure their normal and efficient operation. In addition, pay attention to the maintenance of the compressor, such as regularly replacing the lubricating oil and cleaning the suction filter.
2. Optimization of Ventilation and Airflow
· Duct Cleaning and Maintenance: Formulate a regular duct cleaning plan and use professional cleaning tools, such as duct cleaning robots and high-pressure vacuum cleaners, to remove dust, debris, and dirt from the air ducts to ensure unobstructed air ducts. Meanwhile, check the airtightness of the ducts to prevent air leakage.
· Fan Inspection and Repair: Regularly conduct inspections on fans, checking the operating current, rotation speed, temperature of the motor, and the condition of the blades. For malfunctioning fans, repair or replace them in a timely manner. Consider installing backup fans so that they can be switched in time when the main fan fails to ensure that the air circulation is not affected.
3. Reduction of Heat Load
· Equipment Heat Dissipation Management: For equipment with high heat generation, take effective heat dissipation measures, such as installing cooling fans and water-cooling devices, to dissipate the heat generated by the equipment in a timely manner. At the same time, arrange the equipment reasonably to avoid excessive concentration of equipment and reduce local heat accumulation.
· Personnel Management and Environmental Isolation: Control the number of people in the laboratory and the frequency of their entry and exit to minimize the impact of personnel activities on the laboratory temperature. Set up a buffer room at the entrance of the laboratory to prevent outside hot air from directly entering the laboratory. In addition, provide special work clothes for personnel to reduce the interference of human body heat dissipation on the laboratory environment.
4. Calibration and Optimization of the Control System
· Temperature Sensor Calibration and Replacement: Regularly calibrate the temperature sensors using standard thermometers to ensure that their measurement accuracy is within the allowable range. Once it is found that the error of the sensor exceeds the specified value, replace it with a new one in a timely manner. Meanwhile, pay attention to the installation position of the sensor, which should be selected in an area that can represent the average temperature of the laboratory to avoid measurement deviations caused by improper installation positions.
· Control System Parameter Adjustment: Set the parameters of the control system reasonably according to the actual needs of the laboratory and the performance of the equipment, such as the temperature set value, the refrigeration start-stop temperature difference, and the fan rotation speed. When adjusting the parameters, do it step by step and closely observe the changes in the laboratory temperature to ensure the effectiveness and stability of the parameter adjustment.
In conclusion, the problem of slow temperature drop in constant temperature and humidity laboratories may be caused by multiple factors. We need to conduct a comprehensive inspection and analysis from aspects such as the refrigeration system, ventilation and airflow, heat load, and control system, and then adopt targeted solutions. Guangzhou Cleanroom Construction Co., Ltd. has a professional technical team and rich experience, and can provide all-round maintenance, diagnosis, and solutions for your laboratory to ensure that the laboratory is always in a stable and precise temperature and humidity environment, helping your scientific research and production work proceed smoothly. If you encounter any problems during the operation of laboratory equipment, please feel free to contact us!
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