R32/R134a自复叠热泵变组分浓度实验分析
Experimental study on concentration control of variable components in auto-cascade heat pumps using R32/R134a
司成功 1郭健翔 1孙晋飞 1贺龙彬 1王俊鸿 1刘占杰2
作者信息
- 1. 青岛理工大学 环境与市政工程学院,山东 青岛 266525;青岛理工大学 山东省余热利用及节能装备技术重点实验室,山东 青岛 266525;青岛理工大学 青岛市新能源与节能技术重点实验室,山东 青岛 266525
- 2. 海尔生物医疗股份有限公司,山东 青岛 266000
- 折叠
摘要
为缓解热泵大温度跨度运行时容积制热量衰减严重的问题,提出一种新型变组分浓度调控自复叠热泵实验装置,采用非共沸混合制冷剂 R32/R134a 为工作介质,通过动态监测系统组分浓度分布、制热量、性能系数(COP)等关键性能参数,探究混合工质浓度变化对自复叠热泵循环性能的影响规律.结果表明:冷凝器出水温度或第一级节流阀开度增加,主路低沸点组分质量分数降低 2.5%～8.1%.而随着充注量增加,主路低沸点组分质量分数逐渐增加,排气温度逐渐降低;当充注量增至 2.8 kg,出水温度为 65℃时,COP达 2.22,压缩机排气温度仅为 80℃.当低沸点组分质量分数从 0.3 增加至 0.5,排气温度最高可降低 25.4%.与单级蒸气压缩系统(SVC)相比,自复叠热泵系统排气温度降低 31.2%,以上自复叠热泵组分浓度分布及性能变化规律表明该热泵系统在大温度跨度时具有较明显的性能优势,对于系统长期稳定运行以及节能效应具有显著作用.
Abstract
To solve performance degradation problems of heat pumps under conditions of large operating temperature difference between source and supply waters,a novel auto-cascade heat pump was proposed and tested with a mixed refrigerant of R32 and R134a.The variation of component distribution was experimentally investigated to assess its effects on the system performance.The test results show that the low-boiling component R32 mass fraction dropped by 2.5％-8.1％with the increase of the condenser outlet water temperature and the first electrical expansion valve opening.Moreover,charging more mixed refrigerant could contribute to a lower system discharge temperature and increase the low-boiling component R32 mass fraction at the main cycle.When the system worked with 2.8 kg mixed refrigerant at the condenser outlet water temperature of 65℃,the system COP achieved～2.22,and the compressor discharge temperature can be controlled under 80℃.Meanwhile,the discharge temperature droped by up to 25.4％when increasing the low-boiling component R32 mass fraction from 0.3 to 0.5.Compared with the single-stage vapor compression system,the proposed auto-cascade system presents a perfect performance and lowers the discharge temperature by about 31.2％at the same working condition.This result indicates that the component distribution control of the mixed refrigerant could effectively improve the system performance and contribute to long-term stability and energy-saving.
关键词
自复叠热泵/非共沸工质/变组分浓度/实验研究Key words
auto-cascade heat pump/non-azeotropic refrigerant/variable component concentration/experimental research引用本文复制引用
基金项目
国家重点研发计划(2020YFD1100302)
山东省自然科学基金(ZR2020ME169)
山东省重点研发计划(2022CXPT051)
山东省重点研发计划软科学项目(2022RZB07055)
山东省自然科学基金青年项目(ZR2022QB046)
出版年
2024
国家科技期刊平台
NSTL
万方数据