Industrial refrigeration machines are commonly used in laboratories for key processes such as low-temperature storage of samples, temperature control of reactions, and instrument cooling. Their stable operation directly affects the continuity of experimental processes and the reliability of experimental results. In laboratory settings, refrigerators are prone to various malfunctions due to factors such as variable operating conditions, complex sample characteristics, and high operating frequencies. If not promptly investigated and handled, it may lead to experimental interruption, sample damage, and even instrument malfunction.

1、 Cooling effect decreases

The decrease in cooling effect is one of the common faults of laboratory refrigerators, mainly manifested as the inability to reach the preset low temperature, slow cooling rate, and difficulty in meeting the temperature requirements of experiments. The main causes include three aspects: firstly, refrigerant leakage, aging of pipeline interface seals, damage to valves, or improper operation during maintenance, all of which may lead to refrigerant loss and disrupt the balance of the refrigeration cycle; Secondly, filter blockage can lead to impurities such as dust and sample residues in the laboratory environment easily entering the system, blocking the filter or pipeline, resulting in insufficient circulation flow of the refrigeration medium and decreased heat exchange efficiency; Thirdly, there are abnormalities in the cooling system, such as dust accumulation on the condenser surface, malfunction of the cooling fan, or poor ventilation in the laboratory, which can hinder heat dissipation and affect refrigeration efficiency.

2、 Abnormal operation noise and vibration

A normally operating refrigeration machine has stable noise and slight vibration. If there is a sharp abnormal noise, intermittent roar, or severe vibration, it is a fault signal. The causes of faults are often related to core components: wear of internal parts of the compressor, loose bearings, or insufficient lubricating oil can produce metal friction noise; Fan blades that are deformed, loose, or stuck by foreign objects can cause vibration and noise; The pipeline is not firmly fixed, and abnormal noise may occur due to resonance caused by the flow of the medium during operation. In addition, uneven laboratory floors, unstable equipment placement, or long-term operation leading to loose equipment bases can also exacerbate vibration and noise during operation.

3、 Frequent start stop of equipment

Frequent start stop of refrigeration units not only affects temperature control stability, but also accelerates component aging and shortens equipment service life. Common causes in laboratory settings include improper temperature controller parameter settings, excessively close start and stop temperature thresholds, resulting in frequent triggering of start and stop commands for equipment; Abnormal system pressure, frequent action of high or low pressure protection devices, forcing equipment to shut down and restart; Insufficient cooling medium and low liquid level cause the circulating pump to idle, triggering the protection mechanism to shut down; In addition, frequent opening and closing of laboratory doors and excessive fluctuations in ambient temperature can also cause the refrigeration unit to frequently start and stop due to changes in load.

4、 Pipeline and interface leakage

Leakage faults mainly manifest as refrigerant or cooling medium leakage, which not only affects the refrigeration effect, but may also contaminate the laboratory environment, damage experimental samples, and even cause safety hazards. The main causes are: aging and corrosion of pipelines, long-term exposure to alternating high and low temperature environments, or contact with corrosive gases and sample residues during experimental processes, which can easily lead to pipeline damage; Wear and aging of interface seals lead to a decrease in sealing performance, resulting in medium leakage from the interface; During installation or maintenance, inadequate fastening of pipeline connections or installation deviation of seals can also cause leakage problems.

In summary, in the daily use of industrial refrigeration machines, standardizing operating procedures, regularly cleaning equipment impurities, checking sealing status and medium liquid level can effectively reduce the probability of failures, ensure stable operation of refrigeration machines, and provide reliable temperature support for the smooth development of laboratory work.