In the recent 50 years, with the rapid development of m […]
In the recent 50 years, with the rapid development of modern science and technology, the technology of refrigeration has been changing at a rapid pace. And it is playing an increasingly important role in the fields of modern national economy, people's life, national defense research, culture and the arts. China is one of the earliest countries to use natural cold source. With the progress of society, refrigeration technology has been widely applied to various industries. The role of refrigeration technology is irreplaceable.
Therefore, the design of refrigeration system has become an important part. Refrigeration system design, whether it is assembled into the overall unit manufacturers, or on-site assembly system, the main choice of refrigeration compressors, condensers, evaporators, throttling institutions and fans, motors and automatic control equipment. The steps are to determine the design conditions of the refrigeration system (ie, the selected evaporator (s)) based on the given chilled water temperature (or cooled air temperature), flow rate and inlet temperature and flow rate of the cooling water (or cooling air) Temperature and condensing temperature of the system design parameters of the intrinsic parameters), and then, in accordance with the design conditions of the refrigeration system to select the various components of the equipment, so that each device in the operation of matching each other to give full play to each device's ability to work.
Liquid cooling is not used for general air-conditioning refrigerators. For large refrigerators with low evaporation temperatures (<-5 °C), liquid subcooling is used where possible. That is, do not consider the cold temperature. For the direct evaporative air cooler, due to the low heat transfer coefficient of the air side, in order not to be too large structure size, so take a larger heat transfer temperature difference
However, when a refrigeration unit or a refrigeration system is actually operating, when external parameters (ie, water flow or air flow through the condenser and evaporator, and water or air inlet temperature, etc.) are changed within a certain range , How the performance of the aircraft system changes, the composition of the selected components are properly matched, are designed to consider the issue. In addition, the completion of the design, refrigeration work safety technology, the proper operation of Refrigerated Cold Room equipment, is our inevitable choice in the specific operation.