An investigation of a heat pump system using CO2/propane mixture as a working fluid

In order to decrease the heat rejection pressure of heat pump using pure working fluid, CO₂ or R744, other natural component including hydrocarbons (R290, R600a, R600, R1270, R170, R601) and dimethyl ether (RE170) is added to CO₂, respectively, and then six binary mixtures are achieved. By environmental and thermodynamic comparisons, R290 is selected to be the most appropriate component candidate to mix with CO₂, and meanwhile to weaken the flammability and explosivity for pure R290. Then, the system performances of heat pump using mixture of CO₂ and R290 were experimentally studied when R290 is added to CO₂ with a small fraction, and compared with that of the pure CO₂. The experimental test rig is designed and set up for the transcritical heat pump system. When the refrigerant charge is variable, the heating coefficient performance, optimum heat rejection pressure, compressor power, mass flow rate of refrigerant, and total heat coefficient of gas cooler were researched. The variation ratios of heating coefficient performance and heating capacity with deviation from the optimum refrigerant charge were also investigated. The optimum refrigerant charge of CO₂/R290 is obtained and the research results show that the addition of R290 to CO₂ can efficiently reduce the heat rejection pressure and improve the system performance. The results in the present work could provide useful guidelines for the design and operation of heat pump system using CO₂-based mixture.     

湿法脱硫石膏脱水系统设备配置及优化

石膏脱水系统作为FGD的重要辅助系统,对于吸收塔运行指标、荣液条件、物料平衡、经济运行、副产物综合利用都有重要作用。介绍了湿法脱硫石膏一、二级脱水系统的流程和设备特点,着重分析研究了系统中一级脱水设备、皮带机冲洗系统、滤液水系统、废水旋流设备等的配置、选型和优化方案。     

大气压力对细水雾灭火系统泵组流量特性及效率的影响

柱塞泵是泵组式细水雾灭火系统的关键部件,它是细水雾喷头实施喷雾的供水源和压力驱动源.为研究大气压力,特别是高海拔低气压环境对柱塞泵流量特性及效率的影响,通过在合肥及拉萨两地的对比试验,给出了环境压力与柱塞泵流量特性及效率的关系.结果表明,大气压力减小使柱塞泵的流量减小,因此,在高原低气压环境下使用柱塞泵,应采用增加柱塞泵进口压力的措施,以保证泵组式细水雾灭火系统的设计性能;不同大气压力下泵组的效率无明显变化,即大气压力对泵组的效率无明显影响.     

辛一联合站污油处理的控制措施

介绍了集输泵站污油回收处理的现状，分析了污油回收对泵站正常生产的影响因素，提出了解决办法，使泵站安全、平稳的生产得到了保障。     

某水厂送水泵房选泵方案优化

对南县供水状况进行了简要的介绍,提出了修建水厂的必要性,然后从技术、运行、运行管理费用等方面对送水泵房选泵方案进行了比较,确定了最优方案.     

热油泵房火灾事故分析及控制

运用事故树分析法,对炼化企业高温泵房火灾的原因进行分析,并提出预防措施.     

饮用水中微纳塑料的“胶体泵效应”研究进展

微纳塑料是当今备受关注的新兴污染物,已被证实存在于饮用水流经的各个环节.饮用水中的微纳塑料比表面积大,能够吸附无机物、有机物和微生物,增加其对人体健康的风险危害.微纳塑料与典型污染物的吸附、团聚行为被称为"胶体泵效应".聚焦于饮用水中的微纳塑料,从微纳塑料的赋存情况、胶体泵效应、对人体的毒性作用和胶体泵效应对其去除影响这4个方面进行了总结和阐述.结果表明,微纳塑料广泛存在于水源水、出厂水、管网水和龙头水中,其胶体泵效应促进了与无机物、有机物和微生物的团聚,在加剧微纳塑料毒性的同时,也影响其去除效果.混凝沉淀对微纳塑料的去除效果存在争议,传统砂滤对其去除效果有限,深度处理是去除<5 μm微纳塑料的高效处理工艺.探明微纳塑料胶体泵效应的作用机制和引发条件可有效提高其去除率.最后,从饮用水处理工艺和胶体泵效应的角度,对饮用水中微纳塑料的控制进行了展望,以期为降低微纳塑料在饮用水中的赋存及毒性、保障饮用水质安全和人体健康提供借鉴和参考.     

水源热泵的噪声特性与控制研究

近年来,水源热泵机组由于其具有明显的优势在居民楼供热方面应用越来越广泛,但同时也带来了严重的噪声扰民问题。本文以某住宅小区水源热泵机组的噪声治理为例,通过对现场测量数据的处理,着重分析了水源热泵机组的噪声特性。通过对现场检测分析了噪声声源以及噪声传播路径,进而详细阐述了从吸声和隔声两个方面阻断声音传播以及安装阻尼隔振器隔断振动传播路径进行噪声治理的方案,结果证明,此方案是一套有效的控制措施,降噪效果明显,能完全满足国家技术标准的要求。     

WATER USE CONFLICT NEAR MADISON,NEBRASKA1

ABSTRACT: Nebraska statutes give first preference for use of ground water to domestic purposes, second to agriculture, and third to manufacturing or industrial purposes. Rapid growth in the number of irrigation wells has caused an increasing number of water use conflicts. One such conflict arose from the installation and use of an irrigation well near Madison in Madison County, Nebraska. Pumping from the irrigation well coincided with head declines in nearby domestic wells screened in the same sand and gravel, but appeared unrelated to water level changes in wells screened in a higher saturated sand. A drawdown-recovery test was performed to determine the degree of hydraulic connection between the wells involved. Operation of the irrigation well was determined to be the cause of the head decline in nearby domestic wells screened in the same sand and gravel. Partly as a result of this conflict, legislation recently introduced into the state legislature would require that wells of higher preference be “reasonably” constructed if wells of lower preference are to be held liable for head loss.     

污水处理厂电耗分析与控制

通过对焦作污水处理厂处理工艺特点的研究,分析了其电耗的组成和重点,提出了主要耗电环节的节电措施．每月节约电费12万元。