LNG卫星站冷能与低温太阳能联合发电循环

Combined power generation cycle of cold energy and low-temperature solar energy in LNG satellite station

针对无工业余热可利用的LNG卫星站,提出LNG冷能和太阳能联合发电循环,该联合发电循环可分为LNG冷能发电系统和太阳能热水系统。对LNG冷能发电系统中的设备进行了[火用]分析:换热器内的[火用]损失占流程总[火用]损的69.23%,泵和膨胀机中存在的[火用]损失约占总[火用]损的30.77%;研究了太阳能热水温度、LNG压力、各级膨胀压力等因素对系统性能的影响。使用软件模拟计算得到拉萨地区太阳能集热器各月的集热量和辅助加热量,每年5月至次年1月,太阳能热水系统辅助加热量均低于LNG冷能发电系统的发电量,且富余1.13×10^(5)kW·h的电量。在拉萨2月至4月内,将太阳能热水温度调整至50℃,所需的辅助加热电能均低于LNG冷能发电系统的发电量,且有富余电量。拉萨每年总共可以获得1.344×10^(5)kW·h的电量。夏季LNG冷能发电系统中,冷却后的循环水可以用于冷水空调,冷水空调每年的节电效益为5808元。

For the LNG satellite station without industrial waste heat to be used,a combined power generation cycle of LNG cold energy and solar energy is proposed.The cycle can be divided into LNG cold energy power generation system and solar hot water system.The equipment in LNG cold energy power generation system is exergy analyzed:the exergy loss in heat exchanger accounts for 69.23%of the total exergy loss,and that in pump and expander accounts for 30.77%of the total loss.The effects of solar hot water temperature,LNG pressure and expansion pressure on the system performance are studied.The monthly heat collection and auxiliary heating capacity of solar collectors in Lhasa area are calculated by simulation software.The auxiliary heating capacity of solar hot water system is lower than that of LNG cold energy power generation system from May to January of next year,and the surplus energy is 113×10^(3) kWh.The temperature of solar hot water is adjusted to 50℃within February to April in Lhasa.The auxiliary heating power required is lower than generation of LNG cold energy power generation system,and there is surplus power.Lhasa can obtain a total of 134.4×10^(3) kWh per year.In summer,the cooling circulating water in LNG cold energy power generation system can be used for cold water air conditioner,and the annual power saving benefit of cold water air conditioner is 5808 yuan.