Combined simulation of central HVAC systems with a whole-building hygrothermal model

Due to the lack of building simulation programs that can simulate in details the combined heat, vapor and liquid transfer in porous elements and the HVAC systems, a generic and flexible computational algorithm has been elaborated in order to integrate models for both HVAC systems and multizone building hygrothermal model.     

Application of multicriteria analysis in designing HVAC systems

The present paper discusses a study which aims to develop a method for choosing and managing in the best possible way heating, ventilating and air conditioning (HVAC) systems in new and existing buildings. The method utilises a combination of two analysis’ tools, the multicriteria decision-making and the building simulation towards the direction of a holistic assessment of HVAC systems. In order to evaluate the method, a series of HVAC systems are considered for installing in an office building and the multicriteria method Electre III is applied for their selection. The results show that the proposed model allows the classification of alternative technical solutions concerning the HVAC's design, taking into consideration economic, energy and environmental criteria as well as criteria of users’ satisfaction. Finally, the study also indicates that when applying the sustainability concept in the building sector, and especially in the HVAC systems, this should concern the overall socioeconomic costs.     

A rapid calibration procedure and case study for simplified simulation models of commonly used HVAC systems

A rapid procedure for calibrating simplified building energy simulation models of commonly used HVAC systems has been developed. The procedure developed will allow building professionals to project annual cooling and heating energy consumption of buildings with multiple HVAC systems from short-term field measurement data. This paper describes the general calibration procedure developed, and demonstrates the use of the calibration procedure by applying it to an office building. The calibration methodology requires as little as two weeks of measured hourly heating and cooling consumption data. In the example presented, the simulation model was calibrated using only two weeks of measured heating and cooling data. After calibrating the simulation using this procedure, the RMSE is reduced significantly. The simulation calibrated to two weeks of measured data is then used to simulate the hourly consumption of the building for the year 2004. Comparison of the results of this simulation with the measured data gave monthly CV(RMSE) values of 10.3% and 3.7% for cooling and heating, respectively, which are both well below the 15% values considered acceptable in ASHRAE Guideline 14 [1]. It also shows monthly NMBE values of 2.2% and 1.4% for cooling and heating respectively.     

Integrated simulation through the source-code coupling of component models from a modular simulation environment into a comprehensive building performance simulation tool

No single building performance simulation program contains sufficient capabilities and flexibility to fully respond to the full complexity of modern building design and analysis. Consequently, considerable efforts and advances have been made to facilitate the integrated use of multiple simulation tools to provide more extensive modelling capabilities. The research reported in this article has made a contribution towards the goal of integrated simulation by focusing on the internal coupling of component models from a modular simulation environment into a comprehensive building performance simulation tool. A flexible and extensible facility has been designed and developed to enable the use of HVAC component models (TYPEs) from the TRNSYS simulation program within the ESP-r simulation platform. With this, the source code for any number of TRNSYS TYPEs can be compiled with the ESP-r source code to produce an integrated simulation tool that possesses greater capabilities than either simulation program alone.     

Co-simulation of innovative integrated HVAC systems in buildings

Integrated performance simulation of buildings' heating, ventilation and air-conditioning (HVAC) systems can help in reducing energy consumption and increasing occupant comfort. However, no single building performance simulation (BPS) tool offers sufficient capabilities and flexibilities to analyse integrated building systems and to enable rapid prototyping of innovative building and system technologies. One way to alleviate this problem is to use co-simulation, as an integrated approach to simulation.

This article elaborates on issues important for co-simulation realization and discusses multiple possibilities to justify the particular approach implemented in the here described co-simulation prototype. The prototype is validated with the results obtained from the traditional simulation approach. It is further used in a proof-of-concept case study to demonstrate the applicability of the method and to highlight its benefits. Stability and accuracy of different coupling strategies are analysed to give a guideline for the required coupling time step.     

Improved thermal building management with the aid of integrated dynamic HVAC simulation

Building simulation is a tool that has only recently been recognised as a possible utility to accomplish enhanced building management (Build. Environ. 37 (8–9) (2002) 891). Thermal management however is often neglected. This is due to the complex nature of problems associated with determining the effect of changes to heating ventilating and air-conditioning (HVAC) system properties (Build. Environ. 32(2) (1997)). Effective thermal management is nevertheless a major concern since energy cost and operation cost of buildings are directly influenced by how well the HVAC systems perform (Occup. Med.—State Art Rev. 4(4) (1989)). The aim of this study was to introduce the process of integrated dynamic HVAC simulation as a viable tool to improve thermal management of buildings. This entails both improved maintenance and energy utilisation. The applicability of the integrated simulations was investigated by means of a case study for which a well-verified simulation model was constructed and discussed in a previous article. To illustrate the process of improved management three different scenarios are investigated. Finally the conclusion is drawn that improved management is indeed possible with the aid of integrated simulation.     

TUHVAC：集成化的空调设计分析环境

本文介绍了集成化空调设计分析软件ＴＵＨＶＡＣ的开发思想、主要特点与系统结构。     

暖通空调制冷系统环境性能评价方法研究

通过对HVAC＆R系统环境性能评价方法的回顾,提出了一种新的评价方法。该方法基于专家问卷调查和层次分析法,确定各种环境影响因素的权重系数,根据各类污染物的排放总量和权重系数,计算各类污染物的当量值,将HVAC＆R系统对环境的各类影响转化为一个统一的指标--黑点,从而直观、准确地表达HVAC＆R系统对环境影响的大小。利用新方法对某办公楼空调系统的环境性能进行了模拟计算,结果表明该方法简单直观、切实可行。     

Influence of building parameters and HVAC systems coupling on building energy performance

The performance of different HVAC systems varies when coupled with different buildings. This paper examines the relationship between building heating and cooling load and subsequent energy consumption with different HVAC systems. Two common HVAC systems in use throughout the UK office building stock, variable air volume (VAV) system and fan coil (FC) with dedicated outside air system, have been coupled with a typical narrow plan office building with and without daylight control and for both cellular and open plan.The results presented in this paper clearly indicate that it is not possible to form a reliable judgment about building energy performance based only on building heating and cooling loads. For the two investigated systems, variable air volume system and fan coil with dedicated outside air system, the difference between system demand and building demand varied from over −40% to almost +30% for cooling and between −20% and +15% for heating. If a heat recovery unit is used, the difference in heating performance is even greater, rising to −70%.     

Development of HVAC system simulation tool for life cycle energy management Part 1: Concept of life cycle energy management and outline of the developed simulation tool

The importance of LCEM (life cycle energy management) has been recognized from the view of life cycle energy savings for sustainable buildings. The purposes of this research are the proposal of an LCEM framework and development of prototype HVAC system simulation tools for LCEM. In this paper, the necessity of energy simulation tools for LCEM is discussed, and the outline and solution method of the simulation tool are shown.     

情景模拟教学法在建筑环境与能源应用工程专业实践教学中的应用

为了提高建筑类高校学生的实际工作能力,提出情景模拟的实践教学方法,并以建筑环境与能源应用工程专业为例,制订了三条执行路线。采用情景模拟教学法指导本科生进行毕业设计,可以使毕业设计组内学生相互配合,培养工作能力和沟通能力,并使学生了解行业信息。     

Development of building thermal environment emulator to evaluate the performance of the HVAC system operation

A “performance gap” arises when the actual value of building energy consumption during the operational phase deviates from the value predicted using simulation during the design phase. One cause of this performance gap is that operation is not ideal, as assumed in the simulation, and the control of the heating, ventilating, and air conditioning (HVAC) system is not optimized. These problems occur because the operator has not been trained sufficiently and/or the building automation system is not working as intended by the developer. Both problems are fundamentally caused by the fact that the quality of building operation cannot be quantitatively evaluated by comparison with other buildings because a building is a heterogenous, single-item product. To address the performance gap problem, we developed a method for quantitatively evaluating building operation using a precise simulation based on a thermal environment emulator. The emulator software was developed using the BACnet protocol as an interface to the real world and includes an occupant behavior model to enable the assessment of operation in terms of thermal comfort as well as energy performance. In this paper, we report on the program and network structure of the proposed emulator. In addition, we show the concrete results of changing the operational control, and we assess changes in energy performance and comfort from the perspective of Pareto efficiency.     

建筑环境设计模拟分析软件DeST第10讲暖通空调方案的经济性分析

暖通空调方案的经济性评价是暖通空调设计过程中必不可少的环节,它必须针对暖通空调系统设计由浅入深、逐步深化的过程,在设计的不同阶段,尽可能准确地评价拟采用的暖通空调方案的经济性,从而为优化设计、比较方案提供经济方面的依据。详细阐述了DeST中暖通空调方案经济性分析所选用的模型与模拟方法。以一商用办公写字楼为例,针对暖通空调系统设计过程中的不同阶段,进行了方案的可行性分析和经济性分析,以此介绍经济性分析的方法和如何解决实际问题。     

暖通空调系统几项重点节能设计措施探讨

详细探讨了暖通空调系统的几项重点节能设计措施,主要包括:室内设计计算温度取值、冷热负荷计算、供暖系统设计、风系统设计、空调水系统设计、冷热源选择、补水定压、保温及水力平衡、室温调控与冷热量计量,以供专业人员在工程设计中参考。     

RevitMEP在暖通工程设计中的应用分析

本文结合暖通工程设计实例,探讨、分析基于BIM技术理论的RevitMEP软件在实际工程中应用优势和不足,并提出发展建议。     

某游泳训练馆暖通设计

介绍了某新建游泳训练馆的空调设计,重点讲述了空调负荷计算、采暖通风空调系统的设置及空调系统的气流组织等内容。     

示踪气体跟踪测量方法在空调通风上的应用

论述了示踪气体跟踪测量的基本原理和基本方法。详细介绍了空调、通风工程中使用示踪气体进行检测的内容、计量和过程等,指出了该方法的优点和不足。认为示踪气候跟踪测量在空调、通风工程中能解决系统调节、测量等工作中的具体问题,应用前景广阔。认为“空气龄”应作为评价人空气质量的主要指标之一。     

关于暖通空调系统的节能问题的探讨

近年来,人民生活水平不断提高的同时建筑能耗也在不断的增加,其数景已占全国各项能耗总数的三成以上,而且大有上升之势。本文将对建筑暖通空调系统的节能问题进行研究,并在此基础上提出一些行之有效的策略,以期为我国节能事业的发展做出一点贡献。     

建筑环境设计模拟工具包DeST

建筑环境设计模拟工具包ＤｅＳＴ是基于功能的模拟软件,用于对建筑,方案,系统及水力计算进行模拟,以校核设计,保证设计的可靠性。介绍了ＤｅＳＴ的结构,用户界面,并结合工程实例说明了ＤｅＳＴ的应用。