Classification, installation, commissioning and maintenance of cold storage

1. Classification of cold storage Cold storage, as an important part of modern cold chain logistics, can be classified into many categories according to its purpose, structural characteristics and refrigeration method. According to the nature of use: it can be divided into food cold storage (such as fruit and vegetable cold storage, meat freezer, aquatic quick freezing storage, etc.), pharmaceutical cold storage, scientific research cold storage, industrial raw material cold storage, etc.

According to the structural form: there are mainly modular cold storage and civil cold storage. Modular cold storage is mainly assembled on-site with prefabricated panels, with the characteristics of short construction period and strong flexibility; civil cold storage uses building walls for direct insulation, which is suitable for large-scale and long-term use. According to the refrigeration method: including direct cooling cold storage (evaporator directly exchanges heat with the air in the storage) and air-cooled cold storage (forced circulation of air in the storage through fans, and returned to the storage after cooling by the evaporator), in addition, there are water-cooled cold storage, liquid nitrogen quick freezing storage and other types.

2. Cold storage installation Cold storage installation is a highly technical job, which mainly includes the following steps: Site selection and infrastructure construction: The ground must be flat and solid, and have good ventilation conditions and drainage facilities. For large cold storage, concrete foundations or steel structure brackets need to be prepared in advance. Combined cold storage component installation: According to the design drawings, install the storage body, door, top cover, base and other components in sequence, and ensure that all parts are well sealed without air leakage or water leakage. Refrigeration system installation: mainly includes the positioning, fixing and connection of compressors, evaporators, condensers, expansion valves, pipelines and control systems, and ensure that the refrigerant filling amount is accurate. Wiring and connection of electrical systems: According to the power load and technical specifications, complete the power cable laying, equipment grounding, control line connection and other work.

3. Cold storage commissioning Cold storage commissioning is a key step to ensure the normal operation of cold storage equipment and the temperature in the storage reaches the set standard. The detailed process includes the following aspects: Refrigeration system trial operation: Before the first start-up, a comprehensive inspection of the entire refrigeration system is required to confirm that all valves are in the correct open state, the compressor, evaporator, condenser and other major components are firmly installed, and the electrical circuits are connected correctly. Start the refrigeration unit and observe whether the compressor can start smoothly and enter a stable operating state. Pay attention to the sound of the equipment running. If there is an abnormal sound or excessive vibration, it may indicate a mechanical failure or other problems. Check the pressure values on the high and low pressure sides to ensure that they are within the normal working range. Too high or too low refrigerant pressure may result in poor refrigeration effect or even equipment damage. Observe the refrigerant sight glass to judge the flow condition and purity of the refrigerant. If there are bubbles, oil mist or abnormal color, there may be leakage or contamination.

Temperature control and adjustment: Turn on the temperature control system, set the set value to the required refrigeration or freezing temperature, and start the cooling function. Use the temperature sensor to continuously monitor the actual temperature changes in the warehouse and the working conditions of the temperature controller, such as accurate temperature display and sensitive PID adjustment response. When the temperature in the warehouse is close to the set value, fine-tune the temperature set point and controller parameters according to the actual situation to ensure that the temperature is accurately and stably within the appropriate range required for the storage items. Defrosting system debugging: For air-cooled cold storage, the function of the defrosting system needs to be tested. Automatically or manually trigger the defrosting program after a certain period of time, observe whether the frost layer on the evaporator can be effectively melted, and confirm that after the defrosting is completed, the refrigeration function can return to normal and the warehouse temperature will not fluctuate greatly. Electronic control system detection: Test whether various protection devices such as high-voltage and low-voltage protection, overload protection, and phase loss protection can operate normally to ensure the safe operation of the equipment. Verify the reliability of functional modules such as the alarm system and remote monitoring system to ensure that abnormalities can be discovered and measures can be taken in time.