The atmospheric drain condensate system of a marine steam power plant is described and evaluated from the energetic and exergetic point of view at a conventional liquefied natural gas (LNG) carrier. Energy loss and exergy destruction rate were calculated for individual stream flows joined in an atmospheric drain tank with variations of the main turbine propulsion speed rate. The energy efficiency of joining streams was noted to be above 98% at all observed points as the atmospheric drain tank was the direct heater. The exergy efficiency of the stream flows into the drain tank was in the range of 80% to 90%. The exergy stream flow to the tank was modeled and optimized by the gradient reduced gradient (GRG) method. Optimization variables comprised contaminated and clean condensate temperature of the atmospheric drain tank and distillate water inlet to the atmospheric drain tank with respect to condensate outlet temperature. The optimal temperatures improves the exergy efficiency of the tank as direct heater, to about 5% in port and 3% to 4% when the LNG carrier was at sea, which is the aim of optimizing. Proposals for improvement and recommendations are given for proper plant supervision, which may be implemented in real applications.

中文翻译：

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Lng载热电厂大气排污罐的分析与优化。

从常规液化天然气（LNG）载体的高能和高能的角度描述和评估了船用蒸汽发电厂的大气排放冷凝水系统。计算了在大气排水箱中汇入的单个水流的能量损失和火用破坏率，其中主涡轮推进速度有所变化。由于大气排污罐是直接加热器，因此在所有观察到的点上，加入流的能量效率均高于98％。流入排水箱的料流的火用效率为80％至90％。通过梯度降低梯度（GRG）方法对流至储罐的火用流进行建模和优化。优化变量包括大气排放罐的受污染和清洁的冷凝物温度，以及相对于冷凝物出口温度而言进入大气排放罐的馏出水。最佳温度可将作为直接加热器的储罐的火用效率提高到大约5％（港口）和3％至4％（当LNG运载工具在海上时），这是优化的目的。提出了改进建议和建议以进行适当的工厂监督，可以在实际应用中实施。