冰蓄冷空调系统与常规空调系统的经济比较

以天津某办公大楼为例,比较冰蓄冷空调系统和常规空调系统的经济性。冰蓄冷空调系统的系统造价比常规空调系统高,年运行费用比常规空调系统低,但多出的系统造价可在短期内收回。     

郑州广电中心冰蓄冷空调系统方案分析

根据郑州广电中心空调设计日逐时负荷和郑州市电网现行峰谷分时电价情况，确定选用串联式冰蓄冷空调的运行策略。与常规空调经济性比较后表明，采用串联式冰蓄冷空调可以降低年运行电费，且投资回收期较短。     

复合式空调机组的优缺点分析

对近年来出现的组合式空调机组新的组合形式－复合式空调机组进行了讨论。在占用空间场地，造价，可靠性，能耗等方面，对其优缺点进行了分析。     

诸暨百货大楼冰蓄冷空调设计

介绍了某百货大楼冰蓄冷空调设计。该大楼为国内首例采用国产蓄冰设备的工程，其所用冰球内有双金属蕊芯，且有融冰速度快，释冷强度大等特点。经实测，冰蓄冷空调系统达到设计要求，系统运行三年来，节约电费约２８万元，经济效益显著。     

水蓄冷空调在大型商场中的节能效益显著

该工程是目前国内在建的规模最大的水蓄冷空调项目之一。采用水蓄冷的运行控制方案,水蓄冷负荷仅占峰值负荷的45%。经对该工程的中央空调系统采用水蓄冷方案与常规空调方案的设备初投资、不同运行模式下的年运行电费等方面分析比较,结果表明,采用水蓄冷空调的节能效益十分显著。     

太原某数据机房空调系统设计与节能分析

介绍了太原某数据机房空调系统设计,分析了相关的节能方法与手段。对使用常规冷水机组和带自然冷源的风冷冷水机组两种情况进行了能耗对比分析,得出节能率指标和节电费,为北方地区数据机房空调系统的节能设计提供了参考和依据。     

浅析暖通空调施工阶段造价的控制

本文着眼于对暖通空调施工阶段造价控制进行简单的研究分析。首先简单介绍暖通空调的概念;然后探讨暖通空调施工阶段造价控制的中心内容,主要包括工程计划控制、合同文本控制、变更设计控制等;接下来分析了暖通空调施工阶段造价控制的影响因素,主要有投资目标的分解和外部因素;最后总结了暖通空调施工阶段造价控制的主要措施,如控制材料、控制施工进度等。     

深圳市某建筑物冰蓄冷空调方案设计经济性分析

以深圳市某建筑物冰蓄冷空调设计为依据，对该建筑物集中空调系统采用冰蓄冷方案与常规空调方案作了设备初投资，年运行电费，设备运行寿命，统一电价下的运行电费和主要设备占地面积等方面的比较，说明了采用蓄冷式集中空调系统的优越性。     

联合广场主塔楼空调系统简介

简介了深圳联合广主塔楼水冷冷水柜机空调系统，及其设备选用、设备造价和控制系统。该空调系统在空调实行分户计量、用水冷却和节能方面作出了成功尝试，同时也为今后大型写字楼空调方案的选择开辟了新的途径。     

WTA空调系统

WTA空调系统是近年来空调系统由大到小,由集中到分散演变的一种穿墙式独立空调系统。它设在外墙处或靠外墙处的吊顶中,与建筑物成为一体。WTA空调器内装有空气热泵机组、全热交换器等,可进行空调、采暖、换气,并在过渡季利用新风空调。它适于办公楼、学校类建筑,是一种节能型独立式空调系统。WTA空调机随着质量的提高与造价的下降在设计中将会有越来     

施工项目成本管理技术研究

主要针对当前建筑市场低价竞争和施工企业强化项目成本管理的迫切需要,从成本管理及控制的主要内容入手,分前期成本策划、过程成本控制及核算、实现成本目标的有效途径三方面重点阐述了关于项目成本管理及控制的思路与对策。     

项目成本管理控制信息系统构建模式研究与应用

一个项目的成本管理如果仅仅停留在传统的静态管理方式,缺乏数字化的动态支持,如果不能采用先进成本管理控制信息系统的数字化手段加强管理,很可能使成本管理处于被动状态,所以通过构建成本管理的控制信息系统平台,及时了解成本动态状况,加强企业成本控制能力,从而提高企业管理效益。     

Life-cycle social analysis of motorway bridges

User costs of a bridge are the costs incurred by the users of the bridge, which result from any construction and/or maintenance activity being performed in the bridge. Typically, these costs encompass the additional time lost due to incurred congestion, the additional costs of vehicle operation and the costs of additional accidents. Usually, such costs are not considered in the procedures leading to the formulation of strategies for bridge construction, maintenance and repair, despite their relevance in comparison with the costs incurred by the agency or owner of the bridge. Moreover, in a life-cycle perspective of a bridge, with a time span over 100 years, the quantification of user costs is affected by a large number of uncertainties. Therefore, it is the purpose of this paper to introduce a life-cycle analysis for the quantification of typical user costs, in a probabilistic approach. For this purpose, the analysis of a motorway bridge in Portugal is performed. The results of the case study demonstrate that user costs can be much more important than costs supported by the concessionaire, in a life-cycle perspective, and thus, a much higher importance should be given to these costs apart from the scientific community.     

建筑企业成本漫谈

从时间成本、要约成本、信息成本、安全用工成本、技术经济结合成本、社会效应成本来谈建筑企业的成本。只有全面控制企业的各方面成本,才能获得最大的经济效益。     

Bridge user cost estimation – a synthesis of existing methods and addressing the issues of multiple counting,workzones and traffic capacity limitation

Efforts to incorporate the concerns of bridge users in bridge investment evaluation are often stymied by lack of a comprehensive framework for assessing different user costs. There is a need to synthesise and update existing user cost estimation techniques so that the incorporation of user costs in bridge investment evaluation can be more consistent and streamlined. Secondly, a bridge detour may occur for more than one reason, thus there is a danger of multiple counting that could cause overestimation of user costs. Thirdly, user costs during bridge workzones have rarely been considered in the literature. To address these issues, this article presents a framework for comprehensive estimation of bridge user costs, an approach to address the multiple-counting problem, and a methodology for bridge workzone user cost estimation. Furthermore, the article develops a method to estimate bridge user delay cost due to traffic capacity limitation. The methodologies are demonstrated using a case study.     

Life cycle cost analysis based on the fundamental cost contributors for asphalt pavements

A life cycle costing system should include the key variables that drive future costs in order to provide a framework for reducing the risk of under- or overestimating the future costs for maintenance and rehabilitation activities. In Sweden, price of oil products is mostly affected by the global economy rather than by the national economy. Whereas the price index of oil products has had a high fluctuation in different time periods, the cost fluctuation related to labour and equipment has been steady and followed the consumer price index (CPI). Contribution of the oil products was shown to be more than 50% of the total costs regarding construction and rehabilitation of asphalt pavements in Sweden. Consequently, it was observed that neither Swedish road construction price index (Vägindex) nor CPI has properly reflected the price trend regarding the asphalt pavement construction at the project level. Therefore, in this study, a framework is suggested in which energy- and time-related costs are treated with different inflation indices in order to perform a better financial risk assessment regarding future costs.     

政府工程采购的全寿命周期成本分析

全寿命周期成本为政府采购提供了全新的视角,它要求政府采购应追求产品的全寿命周期成本最小,尤其应该关注环境成本和社会成本,以提高整体社会效益。介绍了全寿命周期成本概念,分析了政府工程采购的全寿命周期成本构成,提出了全寿命周期成本估算方法,介绍了估算中有关参数的确定方法。     

The cost of a package plant membrane bioreactor

The capital and operating costs associated with a small package plant MBR for small-scale domestic duty has been appraised based on a medium-strength municipal wastewater. The three main membrane configurations were considered, these being multi-tube, hollow fibre and flat sheet, with the most appropriate plant design chosen for each configuration. The analysis proceeded via a consideration of the estimated amortised capital costs of the plant individual components and their installation, coupled with operating costs based largely on energy demand and residuals management. Energy demand was calculated from aeration and pumping costs, with aeration based on a combination of empirical relationships for membrane aeration and mass balance, and the modified Activated Sludge Model version 2 used for estimating tank size and sludge generation. Results indicate that it is possible to produce a single household MBR at a capital cost similar to the current market cost for package treatment plants. Desludging and maintenance of these plants is similar but power requirements for an MBR are around 4 times that associated with more conventional package plants. Economies of scale exist from 6-20 p.e. plants but above 20 p.e. there is little cost difference per head, due to the design assumptions made. CAPEX and OPEX are to some extent interchangeable; reductions in CAPEX are associated with an increase in OPEX and vice versa. Whilst costs are high, the market for package MBRs is significantly influenced by the recycling potential of the effluent produced.     

浅谈工程项目成本控制方法

论述了建立工程项目成本控制责任体系的必要性,对项目采购管理中的成本控制进行了探讨,并建立了全流程成本管理体系,以期最大限度地降低项目采购成本。     

Determining the probability distribution of rework costs in construction and engineering projects

Rework arises due to design errors, changes and omissions during design and has been found to contribute to 52% of a project's cost overrun. The statistical characteristics of rework costs experienced from contract award in 276 construction and engineering projects were analysed. The skewness and kurtosis values of rework costs are computed to determine if the empirical distribution of the data follows a normal distribution. The empirical distributions for rework costs are found to be non-Gaussian. Theoretical probability distributions are fitted to the rework data. The Kolmogorov–Smirnov and Anderson–Darling non-parametric tests are used to determine the ‘Goodness of Fit’ of the selected probability distributions. A Generalised Pareto probability function is found to provide the best overall distribution fit for rework costs. The Generalised Pareto distribution is used to calculate the probability of rework being experienced for the selected sample. Projects with a contract value <A$1million had higher rework probabilities than that of >A$101 million. Larger projects may be better managed and longer completion times provide an opportunity to make adjustments to facilitate cost control. The anticipation that rework will occur using the probabilities that are derived can enable a quantitative risk assessment to be undertaken prior to the commencement of construction.