High-pressure steam and hot water often coexist as industrial waste heat. In this study, dual loop and single loop ORC systems are designed for 700 kPa, 4.1 kg/s steam, and 90 ℃, 122.36 kg/s hot water conditions to study the off-design performance when steam or hot water conditions change. To maximize net output power, we employ a particle swarm optimization algorithm to optimize the evaporation and condensation temperatures. The results show that within the specified hot water conditions, the evaporation and condensation temperatures of D-ORC's low-pressure loop and S-ORC increase with rising hot water inlet temperature and flow rate. The S-ORC demonstrates a higher net output power growth rate as hot water flow rate and temperature rise. Under specific steam conditions, when the steam outlet is in a gas-liquid two-phase state, D-ORC's maximum net output power is 1.7 % higher than that of the S-ORC, with little variation in optimal evaporation and condensation temperatures with respect to steam inlet pressure. At a 3.5 kg/s steam flow rate, the D-ORC's high-pressure loop becomes ineffective, whereas S-ORC efficiently adjusts heat exchange capacity under diverse steam-water conditions, Consequently, the D-ORC's average net output power is 34.2 % lower than that of the S-ORC.

中文翻译：

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蒸汽-水双热源 ORC 系统的非设计性能优化


高压蒸汽和热水通常以工业余热的形式共存。在本研究中，双回路和单回路 ORC 系统设计用于 700 kPa、4.1 kg/s 蒸汽和 90 °C、122.36 kg/s 的热水条件，以研究蒸汽或热水条件发生变化时的非设计性能。为了最大限度地提高净输出功率，我们采用粒子群优化算法来优化蒸发和冷凝温度。结果表明，在规定的热水条件下，D-ORC 的低压回路和 S-ORC 的蒸发和冷凝温度随着热水入口温度和流速的升高而升高。随着热水流速和温度的升高，S-ORC 表现出更高的净输出功率增长率。在特定蒸汽条件下，当蒸汽出口处于气液两相状态时，D-ORC 的最大净输出功率比 S-ORC 高 1.7%，最佳蒸发和冷凝温度随蒸汽入口压力的变化很小。在 3.5 kg/s 的蒸汽流速下，D-ORC 的高压回路失效，而 S-ORC 在各种蒸汽-水条件下有效调节换热能力，因此，D-ORC 的平均净输出功率比 S-ORC 低 34.2%。