关键词:

混合制冷剂循环, 循环级数, 热力学模型, 流程模拟

Abstract:

Mixed refrigerant cycles can improve refrigeration efficiency, and are used widely in natural gas liquefaction systems. The effect of mixed refrigerant cycle (MRC) stages on refrigeration performance is significant. Thermodynamics models of the main pieces of equipments in the MRC were built. Natural gas liquefaction processes with MRC were simulated. Most of the process parameters, including shaft power of compressors, refrigeration efficiency and exergy efficiency of different numbers of stages of MRC were obtained. With increasing number of stages of MRC, the shaft power of compressors decreased, while the refrigerant efficiency and exergy efficiency increased. But the rate of decrease and increase declined. Multi-stage cycles made the process configuration complex and operation difficult. Different sizes of refrigeration systems had different optimum number of stages. The larger the size of refrigeration system, the greater the number of stages. A balance must be made between energy efficiency and complexity.

Key words:

混合制冷剂循环, 循环级数, 热力学模型, 流程模拟