The brazed plate heat exchanger (BPHE) has some advantages over the plate-fin heat exchanger (PFHE) when used in natural gas liquefaction processes, such as the convenient installation and transportation, as well as the high tolerance of carbon dioxide (CO₂) impurities. However, the BPHEs with only two channels cannot be applied directly in the conventional liquefaction processes which are designed for multi-stream heat exchangers. Therefore, the liquefaction processes using BPHEs are different from the conventional PFHE processes. In this paper, four different liquefaction processes using BPHEs are optimized and comprehensively compared under respective optimal conditions. The processes are compared with respect to energy consumption, economic performance, and robustness. The genetic algorithm (GA) is applied as the optimization method and the total revenue requirement (TRR) method is adopted in the economic analysis. The results show that the modified single mixed refrigerant (MSMR) process with part of the refrigerant flowing back to the compressor at low temperatures has the lowest specific energy consumption but the worst robustness of the four processes. The MSMR with fully utilization of cold capacity of the refrigerant shows a satisfying robustness and the best economic performance. The research in this paper is helpful for the application of BPHEs in natural gas liquefaction processes.

当在天然气液化过程中使用时，钎焊板式换热器（BPHE）优于板翅式换热器（PFHE），例如安装和运输方便，以及二氧化碳（CO _2）的高耐受性）杂质。但是，只有两个通道的BPHE不能直接应用于为多流热交换器设计的常规液化工艺中。因此，使用BPHE的液化过程不同于常规的PFHE过程。本文对使用BPHE的四种不同液化过程进行了优化，并在各自的最佳条件下进行了全面比较。比较这些过程的能耗，经济性能和耐用性。应用遗传算法（GA）作为优化方法，在经济分析中采用总收益需求（TRR）方法。结果表明，部分制冷剂在低温下回流到压缩机的改进型单混合制冷剂（MSMR）工艺具有最低的比能耗，但在四个工艺中的耐用性最差。充分利用制冷剂冷容量的MSMR表现出令人满意的耐用性和最佳的经济性能。本文的研究有助于BPHE在天然气液化过程中的应用。