Combining a new baseboard radiator with a fan coil system for improving heating performance and reduce energy consumption

In the present work, the heating performance of a new system combined with a new modified baseboard radiator and fan coil is investigated. Using longitudinal fins with special geometry and also forced airflow at the end of the system causes that at the lower inlet water temperature compared with the conventional models, higher heat output rate be obtained. The heat output rate of the new modified system is obtained by experimental metrology based on the European Standard No. EN-442. Temperature and velocity distribution in the room space is done by simulation of the modified system in the Flovent software. Computational fluid dynamics (CFD) results are validated against experimental results and there is a good agreement between them. Also, the energy consumption of the system during the winter season is calculated in TRANSYS software. Experimental results show that the heat output rate of a new modified heating system with inlet water temperature in the range of 45–55°C is on average 4.17 times higher compared with the conventional model. CFD simulation also showed that the combined system provides good thermal comfort conditions. Energy consumption of the new system reduced about 13% compared with conventional models.     

A numerical study on nonlinear DPL model for analyzing heat transfer in tissue during thermal therapy

In the present paper, therapeutic treatment of infected tumorous cells has been studied through mathematical modeling and simulation of heat transfer in tissues by using a nonlinear dual-phase lag bioheat transfer model with Dirichlet boundary condition. The components of volumetric heat source in this model such as blood perfusion and metabolism are assumed experimentally validated temperature-dependent function, which gives more accurate temperature distribution in tissues through this model. We have used the finite difference and RK (4, 5) techniques of numerical methods to solve the proposed problem and obtained the exact solution in a particular case. After comparison, we got a good agreement between them. We have used dimensionless quantities throughout this paper. The effect of relaxation and thermalization time with respect to dimensionless temperature distribution has been analyzed in the treatment process.     

非径向管板焊接接头的超声检测

对AP1000压水堆核电站安全壳贯穿件的非径向管板焊接接头结构特点进行了介绍,并分析其超声检测工艺的重点和难点。通过建立统一的缺陷定位坐标系并结合被检构件的几何特点进行综合分析,推导得出了h值(缺陷回波最高点距套管外壁的距离)的计算方法。为超声检测对这类焊接接头缺陷的准确识别和定位提供了行之有效的方法,为解决这类焊接接头的超声检测技术受限区提供了行之有效的措施。     

酱香型白酒机械化堆积发酵生产试验探究

堆积发酵是酱香型白酒生产过程中重要的工艺环节,本研究通过对机械化堆积发酵试验探究,从堆积发酵温度、时间、入窖糟醅水分、酸度、淀粉、还原糖含量,堆积发酵过程中微生物变化规律以及主要功能微生物变化规律进行探究,并对试验结果的出酒率、优质品率、基酒的相似度与传统工艺进行比较分析。结果表明,机械化堆积发酵试验堆子温度能达到工艺要求,但堆子升温较传统工艺班组慢,堆积发酵时间延长;SPSS显著性分析入窖糟醅水分、酸度、淀粉含量、还原糖含量与传统班组不存在显著差异;堆积发酵过程形成了特有的微生态、生物酶类,富集了大量的酱香风味前体物质与中间体,为后期的窖池发酵奠定了菌系及物质基础,使堆积到达"二次制曲"作用;机械化试验班出酒率、优质品率与传统班组相比存在差距,但差异性不显著;机械堆积发酵不会对基酒色谱成分造成不利影响。机械化堆积仍存在一些不足,将进一步改进完善设备,继续开展试验,调节机械化工艺参数,实现提质增量,促进酱酒机械化推广应用。     

Investigation of the influence of iron-containing abrasives on the corrosion behaviour of the aluminium alloy AlSi1.2Mg0.4

The corrosion resistance of aluminium surfaces is closely linked to the surface state after a grinding process. For years, iron-containing abrasive materials were suspected to lead to increased corrosion susceptibility after processing of aluminium surfaces. To prove a possible correlation between the iron content of an abrasive and the corrosion behaviour of aluminium components, scientific investigations and experimentally practical corrosion tests are necessary. For the current investigation, specimens of a technical Al-Si alloy from the same batch were used. The test specimens were mechanically ground with various resin-bonded model abrasives containing different iron contents. The performed corrosion tests did not reveal a negative influence of the different iron-containing abrasives on the corrosion behaviour of the Al–Si alloy. However, the most sensitive measuring method (electrochemical noise) showed differences in the surface activity depending on the type of abrasive.     

闭式外腔循环太阳能墙集热效果实验研究

文章设计了闭式外腔循环太阳能墙系统,从理论和实验两方面研究太阳能墙传热传质规律。以大连市冬季为研究背景,基于对实验测温点不同时刻的持续监测,从逐时曲线中分析了不同环境下闭式外腔循环系统内部温度以及室内获得热量后室温的变化情况。结果表明,太阳能墙集热效率与太阳辐射强度密切相关,在晴朗天气下,白天部分时段单一太阳能墙就能满足采暖要求,不满足采暖要求时可以选择空气源热泵辅助采暖。     

基于LDRA TBrun软件集成测试的研究

Integration testing is to ensure that each functional module is correct and performs well, so that these modules can be as- sembled together to work well. The manual testing method of the tester alone cannot effectively evaluate the tested aviation soft- ware, and the use of advanced automated testing tools can overcome these difficulties. This paper introduces the method and process of integration testing with Testbed suite tool TBrun through a practical test project.     

汽蚀对离心泵性能影响的实验研究

离心泵长时间运转后,会出现危害严重的汽蚀现象,造成泵性能下降,严重时影响泵的效率、寿命,甚至造成离心泵内部部件损坏。文章通过改变进口压力的方法对单泵、双泵并联、双泵串联等工况下汽蚀对离心泵性能影响进行实验研究。结果表明:当进口压力小于输送液体的饱和蒸汽压时,液体开始发生气化并伴随气泡产生,表明泵内发生汽蚀;汽蚀初期离心泵的效率开始下降,但表现不明显;随着汽蚀不断增大至严重汽蚀区时,Q 1~η曲线出现陡坡,效率出现明显下降并伴随嗡响。实验证明采用提高泵的进口压力等措施可适当减小汽蚀对泵性能的不利影响。     

起重机械防碰装置试验系统的设计

防碰装置是起重机械重要的安全防护装置,其性能质量直接关系到人员和设备安全。常规的防碰装置性能试验方法难以保证试验数据的精度和可靠性。针对防碰装置的工作特点和试验要求,从试验原理、系统结构、运行逻辑等方面入手,设计一套能模拟防碰装置实际运行工况,自动进行性能试验和数据采集处理,精度高、重复性好的试验系统,可以有效提升防碰装置检测能力。