Geothermal energy is a kind of green and non-polluting renewable energy. Medium and low-temperature geothermal energy below 150 °C is usually used directly for heating, industrial and agricultural heating, bathing, etc., and the utilization rate is low. Organic Rankine cycle (ORC) system can be used in a low-temperature geothermal power generation systems. Thermodynamic analysis of the thermal cycle system is carried out in this paper. Based on the principle of exergy analysis, the cycle parameters such as evaporation temperature, condensation temperature, superheating temperature, and supercooling temperature are analyzed. The results show that the exergy efficiency and system output power can improve by increasing evaporation temperature and the exergy loss can decrease in the evaporator. Increasing superheating temperature enhances the output power of the expander and the exergy loss in the condenser, decreases the exergy efficiency simultaneously. Increasing condensation temperature decreases the exergy efficiency of the system and the output power of the expander, and increases the exergy loss of the system. Although the output power of the expander will not be affected by supercooling temperature, the rise of supercooling temperature will reduce the exergy efficiency of the system and increase the exergy loss of the evaporator.

中文翻译：

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有机朗肯循环系统循环参数的能量分析

地热能是一种绿色无污染的可再生能源。150℃以下的中低温地热能通常直接用于取暖，工农业取暖，洗浴等，利用率低。有机朗肯循环（ORC）系统可用于低温地热发电系统。本文对热循环系统进行了热力学分析。基于能值分析的原理，分析了蒸发温度，冷凝温度，过热温度和过冷温度等循环参数。结果表明，提高蒸发温度可以提高系统的火用效率和系统输出功率，并且可以减少蒸发器的火用损失。过热温度的升高会提高膨胀机的输出功率，冷凝器中的（火用）损失，同时会降低（火用）效率。冷凝温度的升高会降低系统的火用效率和膨胀机的输出功率，并增加系统的火用损耗。尽管膨胀机的输出功率不受过冷温度的影响，但过冷温度的升高会降低系统的火用效率，并增加蒸发器的火用损失。