Research On Refrigeration System Of Large Logistics Cold Storage

With the steady development of China's economy,people's consumption concept continues to improve,the cold chain food consumption demand is increasing.At present,China's logistics cold storage is still relatively backward,but the constant progress of the cold chain logistics promote the development of logistics of cold storage,especially ones with the port and large logistics center have attracted much attention.It is a high shelf automatic refrigerated warehouse with multilayer high shelves,requiring computer program control,automatic import and export of goods.A special crane is used to move horizontally and vertically along the track,loading or extracting goods from the shelves,and connecting with the conveyor to realise automatic operation of the goods in and out of the warehouse.Through the analysis of the project,referring to foreign construction experience,completing the following work:(1)Refrigeration system using ammonia as refrigerant liquid for direct gravity formation;selecting four screw compressor with economizer;the liquid ammonia storage cool through tank heat exchanger;using evaporative condenser to improve the heat transfer efficiency;According to different requirements,cold rooms and discharge adopt the full liquid and dry evaporator.The whole cooling system realizes the automatic control of refrigeration equipment such as compressor,ammonia pump and fan,as well as the automatic control and adjustment of main thermal parameters.(2)Through research and comparison,energy saving measures such as new type library board and cushion wood,and the application of double temperature system technology,oil cooling fluid heat recovery device and low ammonia charge design are adopted to improve the efficiency and safety of the unit.(3)According to the characteristics of large span of the cold storage,the air flow of the cooler is studied,and long distance air supply scheme is carried out.After the installation of the refrigeration system and running steadily,and the refrigerating equipment in the engine room is operated automatically.It has reached the international advanced level in the process of automatic refrigeration system.