摘要
为了提高工业高温热泵系统的热力性能,实现对工业低温余热的高效综合回收,提出了一种带中间换热器的双热源高温热泵系统。第一级热泵以CO2为工质、以空气为热源,在超临界状态下将冷水加热到中间温度。第二级热泵以R152a(二氟乙烷)作为工质,从工业余热源吸收热量,将用水加热到所需的高温,并且在中间换热器中将CO2加热到过热状态。对该双热源热泵系统进行热力学分析,发现给定R152a在中间换热器温降的情况下,CO2存在最大的过热度,使得整个系统达到最佳运行工况。以回收50℃废水余热为例与单热源热泵进行比较,平均供水量是后者的两倍多,单位质量热水的耗功量减少43.2%,性能系数和火用效率分别平均提高41.9%和23.96%。
To improve the thermal performance of industrial heat pumps and realize the highefficiency recovery of industrial low-temperature residual heat, a double-heat source hightemperature heat pump system with an intermediate heat exchanger is proposed in this paper and the cold water is heated to high temperatures by two stages for industrial application. First, it is heated to the intermediate temperature by CO2 which absorbs heat from the air, and then, the water is further heated to a high temperature by R152a, taking waste water as the heat source. In the intermediate heat exchanger, the heat of R152a after condensation is recovered by heating CO2 to the superheated state after evaporation. Thermodynamic analysis was conducted and it was indicated that there exists a highest superheated temperature for CO2 when the temperature drop of R152a is given in the intermediate heat exchanger, which shows the best performance of this heat pump system. Compared with the single-heat source heat pump by recovering the residual heat of waste water of 50 ℃, the hot water supply is more than double of it ; the average power consumption per kg of efficiency increase about 41.9 % hot water decreases about 43.2% and the COP and energyefficiency increase about 41.9% and 23.9% respectively.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2014年第11期70-74,80,共6页
Journal of Xi'an Jiaotong University
基金
国家重点基础研究发展计划资助项目(2013CB22b304)
国家自然科学基金青年基金资助项目(51106128)
中央高校基本科研业务费专项资金资助项目
关键词
高温热泵
双热源
中间换热器
热力学分析
high-temperature heat pump
double heat source
intermediate heat exchanger
thermodynamic analysis
