热电厂和集中供热锅炉房吸尘系统设计

介绍了热电厂和集中供热锅炉房吸尘系统主要设备设计及选择原则以及以离心风机为负压源的吸尘系统的设计。     

膨胀水箱容积计算方法

针对膨胀水箱容积计算方法中存在的问题，通过理论分析，给出了计算膨胀水箱容积和系统水容量的修正公式，并给出了相应的计算表格。     

一种消防车用伸缩水管优化计算方法

对消防车用伸缩水管压力损失计算进行了分析研究，提出一种管路优化的计算方法。并使用该方法，分别分析了不锈钢管路和铝合金管路的压力损失特点，通过优化设计，实现了管路减重、降低压损的目标。对臂架变形对优化结果是否影响进行了详细分析，从而保障超高米数登高平台消防车的使用需要。     

An optics inspired optimization method for optimal design of truss structures

This paper presents optics inspired optimization (OIO) as a new optimization technique for optimum design of truss structures with continuous variables. In OIO, the physical laws that govern the image formation in spherical mirrors are artificially modeled to develop a new metaheuristic method. In OIO, the surface of the objective function to be minimized is considered as the reflecting wavy mirror consisting of peaks and valleys. In the reflecting surface, each peak is assumed to reflect as a convex mirror and each valley to reflect as a concave one. By assuming each solution candidate as an artificial object (or light point) that is artificially glittered ray is reflected back by the function surface, the artificial image (new solution) is formed based on the governing equations in physics of optics. Compared with the other existing optimization techniques, OIO seems to be a promising alternative approach for solving truss optimum design problems.     

台阶式重载厂房下滑坡体治理优化设计方法研究

 针对某钨矿须在滑坡体上建设台阶式重载厂房的问题,基于选厂建设与滑坡治理相结合的思路,利用4排悬臂式抗滑桩作为滑体支挡结构,同时兼做选厂内台阶挡土墙基础和选厂厂房基础,充分发挥承载抗滑桩阻滑和承重的双重作用,提出台阶式重载厂房下滑坡体治理优化设计方法。依据传递系数法推导得出考虑上部厂房荷载条件下多排承载抗滑桩抗力分配计算方法,并在此基础上进行钨选厂滑坡推力分配计算和承载抗滑桩结构优化设计研究。有限元法计算结果和基于本文优化设计方案的滑坡体长期监测数据,验证了多排承载抗滑桩抗力分配计算方法和该钨矿滑坡体治理优化设计方法的合理性和适用性。针对现行规范在多排承载抗滑桩抗力分配计算方法上的空白,提出了相应的补充意见。为保证滑坡体上部厂房长期稳定前提下进行滑坡体治理提供了有益的设计思路,也为类似工程的滑坡体治理和厂房等建筑物建设提供了借鉴和参考。     

选煤厂设计优化细节探讨

通过选煤厂的建设实践,对施工图设计过程中的具体优化细节进行了全面探讨,总结出设计时应考虑的几方面,解决了选煤厂存在的使用问题,以达到先进、高效、安全、经济的目的。     

蒸汽溴化锂机组用于热电厂的效益分析

为便于比较电动压缩式制冷机与蒸汽溴化锂吸收式制冷机的性能,在对现有制冷机性能评价指标分析基础上,提出了修正后的电动压缩式制冷机的性能系数———等效性能系数。结合某热电厂制冷空调系统改造工程实例进行了效益计算,结果表明利用热电厂抽汽驱动蒸汽溴化锂吸收式制冷机制冷具有节电效益。     

An optimal manual procedure for ammonia analysis in natural waters by the indophenol blue method

Several procedures for ammonia determination in natural waters by the colorimetric indophenol blue method were tested. Solórzano's procedure, with phenol-alcohol, nitroprusside, alkaline citrate and hypochlorite as reagents, was shown to be appropriate for routine work. An improvement of this procedure was obtained by replacing hypochlorite with sodium dichloro-iso-cyanurate, by adding the catalyst after all other reagents, and by increasing the working pH. Concentration factors are statistically the same as in the original procedure, but the reagent blanks are lower and the color develops faster, both in fresh and in sea water.     

A novel hybrid cellular automata–linear programming approach for the optimal sizing of planar truss structures

This paper presents a novel hybrid cellular automata (CA) linear programming (LP) methodology for the size optimisation of planar truss structures. The method uses the nodal displacements and internal forces of the truss as the design variables of the optimisation problem. The objective function is the volume of the structure and the constraints of the original optimisation problem are recast in terms of the new decision variables in the two-phase step. Starting with an arbitrary set of nodal displacements and internal forces, these are updated in turn in an iterative two-phase process. In the first phase, the internal forces are kept fixed and the nodal displacements are found using a CA approach. In the second phase, a LP is used to find the set of internal forces of truss elements which minimises the total volume of the structure. The effectiveness and efficiency of the methodology is also examined with its application to some benchmark truss structures.     

An optimal model for tunnel lighting control systems

We present a tunnel lighting optimal control model in considering traffic safety and energy-saving problems. Firstly, the demand brightness function with relation to tunnel exterior brightness, traffic flow and speed is described. Then an actual tunnel brightness curve is derived according to lamp equipment layouts and lamp properties in tunnels. Further, a simple method is used to determine an average brightness indicator in tunnels. We present a nonlinear optimal control tunnel lighting model in meeting the demand brightness, total average brightness and minimum dimming ratio constraints and so on. Finally, the simulation results at the JiangBeiLing tunnel of Wenzhou city in China show the optimal control system can meet the demand brightness and total average brightness constraints, and have a notable energy-saving effect.     

An optimal lightweight foamed mortar mix suitable for tunnel drainage carried out using the composite lining method

In this paper, an optimal lightweight foamed mortar mix suitable is proposed for facilitating tunnel drainage carried out using the composite lining method. A physical performance evaluation and pore structure analysis is provided in order to assess the performance of different lightweight foamed mortar mix proportions with various void fractions and foam solution concentrations. Furthermore, on the basis of an in-plane permeability test that simulated the permeation of fines of soil leaking with underground water, the formation and distribution of open-cell foams by measuring the outflow characteristics and outflow volume for each mix of the nonwoven geotextile and lightweight foamed mortar, which are the existing tunnel drainage materials was examined. Consequently, a mix employing a foaming agent with a dilution rate of 2% (#1) showed a better drain performance than all the other mixes, because it had the most appropriately formed and distributed open-cell foams, the key component for tunnel drainage. In other words, the mix of dilution rate of 2% was thought to have achieved stable closed-cell foams because of the decline in the surface tension of the foams, as well as the optimal formation and distribution of open-cell foams that possess excellent permeability because of the cohesiveness between the foams. Moreover, the thickness (drainage space) of it was approximately 17 times that of the nonwoven geotextile, and because the closed-cell and open-cell foams were connected like a spider web, it could be expected to reduce the blocking of drainage caused by the fines of soil.     

Hypolimnetic aeration: field test of the empirical sizing method

A hypolimnetic aeration system was recently installed in a small (16 ha S_α) eutrophic lake and a comparison made between measured performance and predicted performance from an empirical sizing method. The design variables used to size the system were: hypolimnetic volume 451,600 m³; maximum hypolimnetic oxygen consumption 0.2 mg l⁻¹ d⁻¹; aerator input rate 2 mg l⁻¹; water velocity 0.76 m s⁻¹ and depth of air release 12.2 m. A 3.7 kW compressor (0.57 m³ min⁻¹) generated a water velocity of 0.46 m s⁻¹, a water flow of 17.7 m³ min⁻¹ and a theoretical hypolimnetic circulation period of 18 days. Dissolved oxygen increased by an average of 1.6 mg l⁻¹ on each cycle through the aerator, and aerator input rates ranged from 0.6 to 2.6 mg l⁻¹. Hypolimnetic oxygen consumption averaged 0.12 mg l⁻¹ d⁻¹ and ranged between 0.02 and 0.21 mg l⁻¹ d⁻¹. The aeration system was unable to meet the daily oxygen demand (90 kg) as the water velocity was slower than expected (0.46 m s⁻¹). To avoid undersizing future aeration installations the following recommendations should be considered when using the empirical sizing formula: (1) estimates of oxygen consumption should be annual maximums from aerobic hypolimnia; (2) aerator input rates should be conservative (e.g. 1–4 mg l⁻¹) and increase with depth; (3) water velocity of 0.45–0.50 m s⁻¹ should initially be used when no information on actual bubble size or velocity is available; (4) aeration start-up should be timed to avoid periods of accumulated oxygen demands.     

水泥工厂预均化库屋盖柱面网壳优化设计

针对水泥工厂预均化库屋盖结构工程,选取跨度60 m双层柱面网壳进行优化设计,分析了对其性能及用钢量的影响要素,结果表明地震作用对用钢量影响很小,而风荷载是网壳结构设计的控制荷载。     

An algorithm for calculating the optimal reference temperature in buildings

In this paper we present an algorithm for calculating the reference temperature in the rooms of a building. The algorithm works in such a way as to properly reduce the reference temperature in the rooms when they are not occupied, and at the correct start time, before the rooms are occupied, recover the reference temperature back to the defined value. The algorithm is tested in six rooms of a simulated hotel building using the well-known TRNSYS software. Different occupancy regimes are considered in the various rooms, and simulations are performed for a period of 1 year using the weather data of the town of Portoro?, Slovenia. The results obtained with the proposed algorithm are compared to the results achieved with a constant reference temperature setting. The comparison is made with regard to the energy consumed for the heating and cooling of the rooms, and taking account of the deviations from the allowed temperature rise time. In the rooms where the occupancy is not known in advance similar results can be obtained with the proposed algorithm as with the constant reference setting. However, in the rooms where the occupancy is known in advance, desired level of guest comfort can be preserved with the proposed algorithm with an approximately 10% lower energy consumption for the heating and cooling of the rooms than with the constant reference recovery time setting.     

An optimal control algorithm for borehole thermal energy storage systems

The aim of this paper is to present an optimal control algorithm to manage borehole thermal energy storage systems (BTES). Such a system gets exhausted, if it is employed intensively, i.e. outlet fluid is outside acceptable temperature ranges, and can no longer provide the desired heat or cold. To avoid this problem a control algorithm is proposed, which simultaneously optimizes the operation costs. This algorithm is based on a dynamic programming technique and results in an array which provides the optimal heat flux for a given field temperature, date and demand. The controller is illustrated on a simulation of an existing building. Several weather scenarios have been examined and the system remained robust under all situations.     

An integrated performance assessment framework for water treatment plants

An innovative framework for the performance assessment of a traditional water treatment plant (WTP) is presented that integrates the concepts of reliability, robustness, and Quantitative Microbial Risk Assessment (QMRA). Performance assessment for a WTP comprised of three units (i.e., unit 1: Coagulation/Flocculation and Sedimentation; unit 2: Filtration, and unit 3: Disinfection) was conducted. Performance functions for units 1, 2, and units 1 and 2 combined, were constructed by integrating turbidity robustness indices. Performance function for chlorine disinfection was developed based on the difference between achieved and required CT values. A health-based performance function was developed by comparing the target daily infection rate to the site-specific infection rate. It was used to identify whether the health-based target was met during the failures of units 1 to 3. Results obtained from the proposed performance functions can be used by operators to ensure that multiple barriers perform successfully under variable conditions.     

Study of different cogeneration alternatives for a Spanish hospital center

In the present article, the authors analyze different possibilities for providing heating, air conditioning and hot tap water to a hospital center. For this, several cogeneration systems with diesel engines and gas turbines were considered. From the study of the results, it is observed that the size of the facility and the control strategy have a strong influence on the system economy, showing that the most important parameter is the electricity produced. So, the solutions with diesel engines are more efficient than the equivalent ones with gas turbines, since they have a higher electrical performance.     

An analytical queuing network computer program for the optimal egress problem

An analytical queuing network algorithm for the optimal egress problem within buildings is presented with an example of its use and potential application to more general facility types.     

Procedure for selection of the optimal method of installing foundations on permafrost

The need for development of vertical sand drains arose at the experimental testing ground “Ol gino” in a suburb of Grounds are established for the applicability of a new criterion for selection of optimal design solutions, which is a composite of technical and economical characteristics. The procedure is based on probabilistic-statistical calculations of beds and foundations, and concretizes the regulatory requirement of the need for technicoeconomic comparison of alternate schemes. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 19–22, November–December, 1998.     

Component sizing approach for the sandwich plate system

The sandwich plate system (SPS) is a bridge deck system consisting of steel face plates bonded to a rigid polyurethane core. SPS bridges are typically constructed as a series of pre-fabricated SPS deck panels compositely connected with traditional steel girders. The decks are thin, lightweight and modular, and can be tailored to numerous applications including both new bridge and rehabilitated bridges.

With new system, there exist hurdles in the implementation; for SPS, the primary challenge is the lack of an established design method for the panel cross-sections. Presented herein is a method for sizing SPS panel sections for bridge applications. This method is limited to the selection of steel plate and core dimensions, subjected to American Association of State Highway and Transportation Officials (AASHTO) limit states of serviceability, strength and fatigue and does not consider connections or bond aspects of the system. The sizing approach considers the deck panels as plates with variable boundary conditions subjected to the loading conditions of the AASHTO Load Resistance Factored Design (LRFD) bridge design specification. Results from this study indicate that the component sizing for SPS deck panels is controlled by stiffness and that plates selected to satisfy the AASHTO limiting deflection criterion will also be adequate for the remaining serviceability, strength and fatigue limit states.