ORC螺杆膨胀发电机组在不同地域和季节的性能分析

Performance Analysis of ORC Screw Expansion Power Generation Set in Different Regions and Seasons

低品位的中低温余热不能得到有效利用,是能源利用率低的一个主要原因。将该部分余热转化为电能则可获得巨大收益。有机郎肯循环(Organic Ranking Cycle,简称ORC)即是一种利用低沸点的有机工质回收中低温热源的热能并将其转化为电能的技术。不同地域、不同季节气候条件(主要是温度和相对湿度)不同,ORC发电机组的性能也会受到影响。本文在介绍了有机朗肯循环系统结构、原理和特点的基础上,分别采用水冷式、蒸发式以及风冷式三种冷凝器,利用NIST软件在Matlab界面下对系统进行计算,分析得到了不同地域和季节气候条件的变化对系统冷凝温度、发电量和发电效率的影响。

Poor usage of low-grade waste heat at low and medium temperature is one of the main causes for unsatisfactory energy utilization efficiency. Huge benefit can be obtained by conversion from waste heat to electric energy. Organic rankine cycle （ORC） is an efficient method using working fluids with low boiling point. The ORC system＇s efficiency is affected by spatial and seasonal variations （primarily the air temperature and relative humidity）. This paper introduces the structure, operation principle and main features of the ORC system. Three types of condenser （water-cooled, evaporative and air-cooled） are adapted into the system. The overall performance is calculated using Matlab with thermodynamic properties provided by NIST. The calculation results lead to influences on condensing temperature, electric energy production and system efficiency by spatial and seasonal variations.