In high-low temperature test chambers, refrigerant leakage is a critical issue affecting stable operation during low-temperature testing. As the core medium of the refrigeration system, refrigerant leakage not only leads to a decreased cooling rate and abnormal temperature fluctuations, but can also cause system pressure imbalances and even compressor damage. Therefore, a multi-dimensional protection system must be built, encompassing equipment design, installation and commissioning, daily maintenance, and emergency response, to minimize leakage risks.
The equipment design phase is the primary step in preventing refrigerant leakage. The refrigeration system of the high-low temperature test chamber must use high-strength, corrosion-resistant piping materials, such as copper or stainless steel pipes, and ensure that pipe connections use welded or dedicated compression fittings to avoid leaks caused by loose threads or aging seals. Simultaneously, the layout of the refrigeration system should be rationally planned to reduce pipe bends and intersections, lowering the risk of pipe rupture due to vibration or stress concentration. Furthermore, the equipment should be equipped with a pressure protection device that automatically shuts down when system pressure is abnormal, preventing pipe bursts due to excessive pressure.
The installation and commissioning phase is crucial for the sealing performance of the refrigeration system. During equipment installation, professional technicians must strictly adhere to operating procedures for pipe connections and sealing. For example, when welding pipes, welding temperature and time should be controlled to avoid pinholes or cracks; compression fittings must ensure a tight fit between the fitting and the pipe, and the seal must be verified through pressure testing. During the commissioning phase, a comprehensive leak test of the refrigeration system is required. This can be done using a nitrogen pressurization method, where high-pressure nitrogen is introduced into the system, and then soapy water or a professional leak detector is used to check for bubbles or leak signals at each connection point. The system can only be put into use after ensuring there are no potential leaks.
Routine maintenance is crucial for long-term refrigerant leak prevention. The high-low temperature test chamber should be regularly checked for the refrigeration system's operating status, including the temperature and pressure parameters of key components such as the compressor, condenser, and evaporator, as well as the external integrity of pipes and joints. If oil stains or frost are found on the pipe surface, it may indicate a refrigerant leak, requiring immediate shutdown and inspection. Simultaneously, the sealing rings and desiccant filters in the refrigeration system should be replaced regularly to prevent leaks due to aging sealing rings or desiccant failure. Furthermore, the equipment should be kept clean to prevent dust or debris from entering the refrigeration system and affecting the normal operation of components.
Environmental control has a significant impact on the stability of refrigeration systems. High-low temperature test chambers should be placed in well-ventilated environments with suitable temperatures to prevent excessive load on the refrigeration system due to high temperatures or reduced refrigerant flow due to low temperatures. Sufficient space should also be provided around the equipment for heat dissipation and maintenance. If the equipment is to be used in humid or corrosive environments, the refrigeration system must be treated with anti-corrosion measures, such as applying a protective coating or using stainless steel, to extend the equipment's lifespan.
Proper operating procedures are crucial to preventing refrigerant leaks caused by human error. Operators must receive professional training and be familiar with the equipment's operating procedures and precautions. For example, during low-temperature testing, frequent start-ups and shutdowns should be avoided to prevent pipe ruptures due to sudden changes in system pressure. When adding refrigerant, the type and dosage specified in the equipment manual must be strictly followed to avoid system malfunctions caused by mixing or over-adding refrigerants. Furthermore, after the equipment is shut down, maintenance operations should only be performed after the system pressure has equalized to prevent refrigerant spraying due to pressure differences.
Emergency response mechanisms are the last line of defense against refrigerant leaks. If a refrigerant leak is detected, immediately shut down the machine and disconnect the power supply. Simultaneously, open doors and windows for ventilation to reduce the refrigerant concentration indoors and prevent poisoning or suffocation. If the leak is large, use specialized equipment to recover the residual refrigerant to avoid environmental pollution. Then, contact professional maintenance personnel for a comprehensive inspection of the equipment, locate and repair the leak, replace damaged parts, recharge with refrigerant, and conduct pressure tests and performance verification to ensure the equipment returns to normal operation.
Preventing refrigerant leaks during low-temperature testing in high-low temperature test chambers requires continuous management throughout the equipment's entire lifecycle. Through comprehensive measures such as optimized design, standardized installation, regular maintenance, environmental control, standardized operation, and emergency response, the risk of leaks can be significantly reduced, ensuring stable equipment operation and providing reliable environmental conditions for low-temperature testing.
