会泽县冷流水池塘养殖水质综合治理技术

为推进水产产业提质增效和水产养殖尾水达标排放,会泽县5年内累计开展池塘标准化改造和尾水治理200hm2,实践探索多种水质提升技术措施,最终形成会泽县“冷流水池塘养殖前中后”水质综合治理技术。经水质检测结果证实,会泽县“冷流水池塘养殖前中后”水质综合治理技术措施是有效可行的。

山区冷流水培育秦岭细鳞鲑苗种技术要点

总结了甘肃省天水市秦岭细鳞鲑驯养繁殖场多年来利用山区冷流水培育秦岭细鳞鲑(Brachymystax lenok tsinlingensis)苗种的关键技术,孵化的仔鱼上浮开口后经90 d左右的培育,平均体长达到9.60 cm,平均体重达到10.00 g,实现苗种人工规模化培育,使得该物种资源量在人工干预条件下实现有效扩增。

西部山区冷流水养殖及尾水处理技术

我国西部山区多处在高海拔地区,冷水资源十分丰富,水质清澈,水温较低,适宜开展鲑鳟等冷水性鱼类流水养殖。本文结合实际对山区冷流水养殖的选址、建造、尾水治理等技术进行阐述,重点介绍了冷流水鱼场的布局和建造技术,以期为开展冷流水养殖提供参考依据。

浅谈山区冷流水养鱼技术要点

山区一般地下水、泉水和水库自流水较为丰富，流量大，十分有利于大规模的发展冷水养鱼，因地制宜的利用冷流水进行养鱼，不仅可以节约养殖成本，增加养殖产量，提高养殖户的收入，还是我市以特色、高效为突破口，走特色渔业发展之路有效途径之一。因此建立规模化冷流水特色养殖场，为我市渔业经济发展柘宽了道路，促进渔业产业的健康发展。为了保证山区冷流水养鱼的有序进行，我市渔业管理站根据特有的水质，实地的调查研究，寻求养鱼技术的突破。

天津铁厂自焙炭砖及自流水冷综合炉底实践

天津铁厂与武汉钢铁设计研究院合作,于1983年在大修的4号高炉(550m^3)上试用了自焙炭砖炉村,主要用于炉底和炉缸部位。炉底共砌砖10层,总厚为3450mm。其中下面8层为满铺自焙炭砖,上面面层为环砌自焙炭砖,中间砌二层高铝砖保护层。炉缸在风口大套下沿环砌9层自焙炭砖。

自焙炭砖及自流水冷综合炉底的生产实践

介绍了自焙炭砖的原料、成型及其结构特性,自焙炭砖的炉内焙烧及其变化机理,天津铁厂高炉“自焙炭砖自流水冷综合炉底”的结构特性,并经生产实践及工业性试验的检验是成功的,首创了我国中型高炉的一种新的炉底结构模式,为在我国大型高炉推广使用自焙炭砖提供了实践经验。

对昭通市冷流水养殖技术的探讨

云南省昭通市水资源十分丰富,适合发展水产养殖业。最近几年,随着农业产业结构不断调整,水资源成为昭通市农民群众发家致富的重要资源。利用昭通市优质的水资源,积极发展冷水鱼养殖技术,是昭通市未来需要重点发展的产业。冷流水养殖技术是近几年在昭通市发展起来的水产饲养技术,冷流水资源丰富,开发利用较少,具有很大的发展潜力。但是由于地势险峻、场地修建困难、交通运输不方便,导致冷流水养殖的发展比较缓慢。笔者结合养殖经验,就冷流水养殖技术进行了分析。

昭通市渔业发展调查

为充分开发昭通市丰富的渔业资源,加快全市渔业产业发展进程,促进农业增效、农民增收.根据市政府要求及市农业局安排,市渔业部门重点围绕电站库区渔业开发、冷流水资源利用、稻田及池坝塘养鱼等方面深入进行调研,并在充分研究和征求专家意见的基础上,形成以下调研报告.

Application of water loop variable refrigerant flow air-conditioning system in large-scale buildings in northern China

A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow（VRF）air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.

Optimum control strategy for all-variable speed chiller plant

The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation model of water source chiller plant established in dynamic transient simulation program (TRNSYS),the four-variable quadratic orthogonal regression experiments were carried out by taking cooling load,cooling water supply temperature,cooling water flow rate and chilled water flow rate as variables,and the fitting formulas expressing the relationships between the total energy consumption of chiller plant with the four selected parameters was obtained. With the SAS statistical software and MATHEMATICA mathematical software,the optimal chilled water flow rate and cooling water flow rate which result in the minimum total energy consumption were determined under continuously varying cooling load and cooling water supply temperature. With regard to a chiller plant serving an office building in Shanghai,the total energy consumptions under different control strategies were computed in terms of the forecasting function of cooling load and water source temperature. The results show that applying the optimal control strategy to the chiller plant can bring a saving of 23.27% in power compared with the corresponding conventional variable speed plant,indicating that the optimal control strategy can improve the energy efficiency of chiller plant.

Experimental Studies on Critical Heat Flux in a Uniformly Heated Vertical Tube at Low Pressure and Flowrates

Investigations into critical beat flux at low flow and pressure conditions are of particular interest when predicting the nuclear reactor core behavior during Loss of Coolant accident （LOCA）. Therefore, critical heat flux （CHF） has been investigated in a uniformly heated vertical round tube at two low system pressures and six low water flowrates. The results have been compared with two correlations which have different approaches and CHF look-up table. Good agreements have been obtained for the three comparisons at the lower sets of mass fluxes. The Bowring correlation was found to be the best to correlate the experimental results with Root Mean Square Error RMSE of 0.54% and 0.56% for the 5 bar and 15 bar system pressure respectively. A comparisons with the Shim and Lee correlation yielded RMSE of 0.23% and 5.74% for the two system pressure respectively. When the look-up table of Groeneveld et al. was used, RMES of 0.55% and 25.2% was obtained for the two system pressure respectively.

Influence of Cooling Systems on the Behaviour of Dairy Cows Housed in Cubicle Barn

The aim of this paper is to collect information about dairy cow＇s behaviour connected to different environmental conditions. During summer 2009 and winter 2010 experimental trials were arranged to verify the behaviour of dairy cows in a farm located in Po Plain （Italy）. The barn was provided with an air-water cooling system, based on the use of fans and sprinklers placed only in the feeding alley. Two different trials were carried out. The first experiment was targeted on verifying the use of the cubicles by the cows in relation to the availability of the cooling system only in feeding area. The second trial aimed at testing the effectiveness of zone cooling systems placed in the front of cubicles. For this purpose three cubicles in the barn were provided with cooling systems, based on the input of high velocity conditioned air streams. The results clearly remark that the behaviour of the animals is greatly influenced by the environmental conditions. With high temperatures the use of the cubicles is deeply reduced and the animals prefer to stay in feeding area, thus benefiting from the cooling effect of water sprinkled by the showers and of the air streams created by the fans. With air temperatures increasing from 21℃ to 33 ℃ the cows reduce the staying in the cubicles, which gets down from 540 to 32% （r2 = 0.2608）. As regards the efficacy of zone cooling system in the cubicles, the results are not particularly encouraging. The cows continue to use the cubicles without changing the behaviour in relation to the presence of conditioned air flow.

Three Dimensional Numerical Simulation of Convection-Condensation of Vapor with High Concentration Air in Tube with Inserts

A three-dimensional numerical model is presented for studying the convection-condensation of mixture with vapor in a tube with edgefold-twisted-tape inserts under transition flow.According to the diffusion layer theory and laminar species transport,a condensation model with user defined function is proposed and compared with heat and mass transfer analogy and experimental test.With the condensation model,the influences of gap width and op-erating parameters on thermal-hydrodynamics performance are simulated.As the gap width increases,convection and condensation heat transfer increase initially and then decrease,while convection heat transfer increases sharply and then decreases slightly.Increasing vapor fraction has a significant effect on condensation heat transfer but it has little effect on convective heat transfer.With the increase of inner wall temperature both convection and condensa-tion heat transfer all decrease and the ratio of condensation to total heat decrease dramatically.Increases inlet tem-perature mainly affects convection heat transfer.

Mechanical Ventilation Strategy for Subway Cabins Using Numerical Simulations

Seoul metropolitan subway network is known to be the one of the most heavily used transportation means in the world. The subway cabins are naturally ventilated when the cabin doors are opened and through the gaps caused by the incomplete air-tightening of cabin bodies. Although, subway trains are equipped with a mechanical exhaust fan, the apparatus is rarely operated due to the problem of heating/cooling efficiency especially in the summer and winter seasons. In this study, we analyzed the transient CO2 （carbon dioxide） concentration level during the journey of a subway cabin when a heavy load of passengers of up to 200% of designed capacity using a CFD （computational fluid dynamics） analysis. With an increased journey time, the CO2 concentration increased by up to 5,000 ppm depending on passenger load. Through the operation of a mechanical exhaust fan, the high concentration of CO2 decreased down to 1,500 ppm. The effect of the exhaust fan operating on the dilution of indoor air was estimated by comparison with a closed cabin. In addition, the energy consumption for cooling in summer time was assessed for exhaust fan operations.

Measurement of thickness and heat transfer coefficient of water film out of tube in an evaporative air cooler

Thickness of falling water film out of tubes is one of critical factors of heat transfer of evaporative air cooler. A new method of resistance measurement was developed to measure thickness of the film. When the resistance probe on the tip of micrometer touches the surface and bottom of the film, two corresponding sudden reductions of resistance occurs, and the difference of two graduations on the micrometer displays the thickness of the film. The film thickness of eleven angles was measured in five kinds of water flows and results varies from 0.8933mm to 1.7233 mm. Mean thickness and mean heat transfer coefficient of the film out of the tube was calculated.

防脆硫化黑轧染试验小结

防脆黑的试验成功不但在经济上有现实意义,而且在政治上有其重大的意义。我厂在省、市、局的正确领导下,接受了“三部”联合下达的防脆硫化黑染料新工艺试验的政治任务。在厂革委会和驻厂军代表的领导和大力支持下,成立了由工人、干部、技术人员参加的“三结合”小组,为了更好更快的完成这一光荣的任务,学习了兄弟省、市试验的先进经验,特别是上海防脆黑试验小组的同志对我们帮助很大。

防脆硫化黑染料初步试用情况

在无产阶级文化大革命的伟大的胜利的凯歌声中,防脆硫化黑染料在我国初步试制成功,并在常州染料厂投入了试生产,它的试制成功从根本上解决了硫化黑的脆布问题,具有极其重大的政治、经济意义,这是我国工人阶级坚决贯彻毛主席的“备战、备荒、为人民”和“中国人民有志气,有能力,一定要在不远的将来,赶上和超过世界先进水平”伟大方针而取得的新成就。我厂在上级革委会的关怀下。

Experimental investigations on the heat transfer characteristics of micro heat pipe array applied to flat plate solar collector

This paper introduces a novel fiat plate solar collector （FPC） using micro heat pipe array （MHPA） as a key element. To analyze the thermal transfer behavior of flat plate solar collector with micro heat pipe array （MHPA-FPC）, an indoor experiment for thermal transfer characteristic of MHPA applied to FPC was conducted by using an electrical heating film to simulate the solar radiation. Different cooling water flow rates, cooling water temperatures, slopes, and contact thermal resistances be- tween the condenser of MHPA and the heat exchanger were tested at different heating powers. The experimental results in- dicate that MHPA-FPC exhibits the enhanced heat transfer capability with increased cooling water flow rate and temperature. Total thermal resistance has a maximum decline of approximately 10% when the flow rate increases from 180 to 360 L h-1 and 38% when the cooling water temperature increases from 20~C to 40~C. When the inclination angle of MHPA-FPC ex- ceeds 30~, the slope change has a negligible effect on the heat transfer performance of MHPA-FPC. In addition, contact thermal resistance significantly affects the heat transfer capability of MHPA-FPC. The total thermal resistances lowers to nearly half of the original level when contact material between the condenser of MHPA and the heat exchanger changes from conductive silicone to conductive grease. These results could provide useful information for the optimal design and operation of MHPA-FPC.

Flow field optimization and design for a Spallation Neutron Source target cooling system

Cooling water is an important part in a Spallation Neutron Source target cooling system, but the unstable vortexes at the exits of the slits between every two tungsten target slices have a negative impact on the stable running of the target system. We apply the field synergy principle for fluid flow to obtain the optimal flow field, which has a uniform velocity distribution without eddy, and then, optimize the geometrical structure of the cooling water flow channel based on the optimal flow field. The results show that when the cooling water flows in the optimized channel, the eddy sizes decrease, the time fluctuations of velocity and pressure almost vanish, and the volume flow rates of the cooling water in each parallel slit are uniform. Therefore, it effectively improves the running stability of the target system with the premise of satisfying the target heat load.

Improving Film Cooling Performance by Using One-Inlet and Double-Outlet Hole

The film cooling performance of a trunk-branch hole is investigated by numerical simulation in this paper. The geometry of the hole is a novel cooling concept, which controls the vortices-pair existing at the mink hole outlet using the injection of the branch hole. The trunk-branch holes require easily machinable round hole as compared to the shaped holes. The flow cases were considered at the blowing ratios of 0.5, 0.75, 1.0, 1.5 and 2.0. At the low blowing ratio of 0.5, the vortices-pair at the outlet of the trunk hole is reduced and the laterally coverage of the film is improved. At the high blowing ratio of 2.0, the vortices-pair is killed by the vortex which is produced by the injection of the branch hole. The flow rate of the two outlets becomes more significantly different when the blowing ratio increases from 0.75 to 2.0. The discharge coefficients increase 0.15 and the laterally averaged film effectiveness improve 0.2 as compared to the cylindrical holes. The optimal blowing ratios occur at M=1.0 or M= 1.5 according to the various locations downstream of the holes.