Development of DC Inverter Scroll Compressor used for Marine Container Refrigeration Unit

In recent years, energy saving of a container ship is becoming one of the most important issues from the point of environmental protection of the global marine transportation business. To solve this problem, we have developed a new gas injection inverter scroll compressor for marine container refrigeration unit. The new compressor is based on a conventional scroll compressor, which has been used in various industrial air conditioners for a long time, with some greatly improved technologies. For instance, the efficiency of the compressor is increased by optimizing the gas injection mechanism. On top of this, the efficiency at low speed operation is increased by using interior permanent magnet synchronous motor. As a result, it was possible to achieve higher refrigeration capacity without increasing the size of the new compressor. The energy consumption has decreased by 45% compared to conventional models. This paper describes details about the improvements of the compressor including the gas injection mechanism and the improvements in its performance at low speed operation