The Experts below are selected from a list of 4704 Experts worldwide ranked by ideXlab platform

Shengwei Wang - One of the best experts on this subject based on the ideXlab platform.

  • coordinated demand controlled ventilation strategy for energy efficient operation in multi zone Cleanroom air conditioning systems
    Building and Environment, 2021
    Co-Authors: Chaoqun Zhuang, Kui Shan, Shengwei Wang
    Abstract:

    Abstract Cleanrooms can be 10–100 times as energy-intensive as typical office buildings. The causes of this are mainly high air change rates and counteraction (i.e. overcooling and reheating) processes in applications. Existing studies have addressed the design and control of outdoor and supply air ventilation systems separately without considering the interaction between them, which causes significant energy waste. This study therefore proposes a coordinated demand-controlled ventilation (CDCV) strategy to achieve energy-efficient operation in multi-zone Cleanroom air-conditioning systems, by coordinating operation between outdoor and supply ventilation systems. The Lorenz curve and Gini index are introduced to quantify the demand diversity of multiple zones, and degrees of overcooling and overdrying are used to quantify the mismatch between cooling supply and demand. Cleanrooms in a pharmaceutical factory located in Hong Kong, a humid sub-tropical city, are selected to test and validate the effectiveness of the proposed strategy. Test results show that the optimization of supply air volume can alleviate the mismatch between cooling supply and demand, as well as affect the optimal outdoor air ventilation mode. The proposed strategy can achieve up to 89.6% of reheating and 63.3% of overall energy savings.

  • an adaptive full range decoupled ventilation strategy for buildings with spaces requiring strict humidity control and its applications in different climatic conditions
    Sustainable Cities and Society, 2020
    Co-Authors: Chaoqun Zhuang, Shengwei Wang
    Abstract:

    Abstract The buildings with spaces, requiring strict temperature and humidity controls, such as Cleanrooms, are usually very energy-intensive due to improper system design and operation. To address this challenge, a novel “adaptive full-range decoupled ventilation strategy” (ADV strategy) is proposed, which incorporates the advantages of different operation modes and offers energy-efficient operation. In this paper, the energy and economic performance as well as the recommended operation modes of the ADV strategy are investigated under different climatic conditions. The energy performance of a typical pharmaceutical Cleanroom air-conditioning system is evaluated by simulation tests in nine cities in five typical climate zones. The test results show that adopting the ADV strategy can achieve 6.8–40.8% energy savings compared with that of a most commonly used existing ventilation strategy. Dedicated outdoor air ventilation (DV) is recommended as the main mode of the ADV strategy in severe cold/cold/moderate climate zones while the following sensible load (FS) is recommended as the main economizer mode in hot/temperate climate zones. For existing system retrofits and new system designs, the payback periods are less than 4 years and 2 years respectively in most climates when the ADV strategy is fully implemented.

  • probabilistic optimal design of Cleanroom air conditioning systems facilitating optimal ventilation control under uncertainties
    Applied Energy, 2019
    Co-Authors: Chaoqun Zhuang, Shengwei Wang, Kui Shan
    Abstract:

    Abstract Buildings with spaces requiring strict temperature and humidity controls, such as pharmaceutical Cleanrooms and semiconductor/microchip factories, have been growing very quickly in terms of total floor area and energy consumption. In such buildings, much of the energy is unnecessarily wasted due to the incoordination of system design and operation/control, especially under “off-design” and ever-changing ambient and load conditions. This paper, therefore, proposes a probabilistic optimal design method for Cleanroom air-conditioning systems facilitating optimal ventilation control under uncertainties. To consider the effects of asynchronous loads in different zones/spaces with reduced computation demand, a probabilistic diversity factor method is proposed which is a simplified method to quantify the effects of uncertainties of space load diversities in multiple zones/spaces using diversity factors. The proposed design method is implemented and validated in the design optimization of air-conditioning systems for implementing four different ventilation control strategies considering possible and uncertain off-design conditions. The energy and economic performance as well as service satisfaction of the air-conditioning systems are also evaluated and compared. Results show that the proposed design method can obtain the optimal air-conditioning systems with minimum life-cycle cost and superior satisfaction of service.

  • energy efficient design and control of Cleanroom environment control systems in subtropical regions a comparative analysis and on site validation
    Applied Energy, 2017
    Co-Authors: Kui Shan, Shengwei Wang
    Abstract:

    Abstract Compared with spaces air-conditioned for thermal comfort, Cleanrooms often have special requirements on dry bulb temperature, relative humidity and particle concentrations. It is a challenging task to achieve those requirements with minimum energy consumption, especially when different parameters interfere with each other. A significant amount of energy would be wasted if the system is not properly designed and controlled. This paper firstly provides an overview and a discussion on the essentials for design and control of Cleanroom air-conditioning systems. The existing systems and controls are categorized into three typical options and their performances are then analyzed based on different weather and load conditions. For new design, the “fully decoupled option” is the preferred option for humid sub-tropical regions. The analysis results are applied in a retrofit project for a pharmaceutical factory located in Hong Kong, a humid sub-tropical city, which employed the “interactive option”. This system is proposed to operate as a “partially decoupled option” in this project since such retrofit requires no modification on the existing hardware. The retrofitted system option has been on-site tested in mild weather condition, which provided 69.6% and 87.8% reductions of cooling and heating consumptions respectively. More comprehensive comparison tests are also conducted on a dynamic platform built on Matlab/Simulink.

Joshua M Pearce - One of the best experts on this subject based on the ideXlab platform.

  • compatibility of 3 d printed devices in Cleanroom environments for semiconductor processing
    Materials Science in Semiconductor Processing, 2019
    Co-Authors: Toni P Pasanen, Ismo T.s. Heikkinen, Joshua M Pearce, Guillaume Von Gastrow, Hele Savin, Ville Vahanissi
    Abstract:

    Abstract 3-D printing has potential to revolutionize manufacturing of customized low-cost scientific equipment, and numerous self-designed applications have already been realized and demonstrated. However, the applicability of 3-D printed devices to Cleanrooms used for semiconductor processing is not as straightforward, as the controlled environment sets strict requirements for the allowed materials and items. This work investigates the opportunity to utilize 3-D printing in Cleanrooms by analyzing three potentially suitable polymers (polylactic acid (PLA), acrylonitrile butadiene styrene (ABS) and polypropylene (PP)) for two applications that do not require particular chemical compatibility: a custom single wafer storage box and a wafer positioner for a metrology system. The designed equipment supplements commercial selection by introducing support for samples with non-standard shape or size and simultaneously reduces the price of often extensively expensive Cleanroom equipment. The results show that the single wafer boxes 3-D printed from PLA and ABS generate as little particles as a commercial equivalent, whereas slightly more particles are found from a wafer stored in the self-printed PP box. Nevertheless, the number of particles on all wafers is in the same order of magnitude, indicating that 3-D printed boxes are not significant particle sources. The 3-D wafer positioner seems to cause a negligible particle increase on the manipulated wafer, while abrasion of the mechanical parts generate larger numbers of particles that may disperse in the environment. Regular cleaning of those parts is thus recommended, and applicability in a Cleanroom environment will depend on the cleanliness constraints. Elemental analysis reveals that 3-D printed objects contain no other harmful metal impurities than those originating from colorants. Thus, 3-D printing filaments with natural color should be preferred for purposes, where metal contamination could be an issue, including semiconductor processing. Finally, 3-D printing filaments considered in this study are shown to be resistant to isopropanol and deionized water, which is critical for efficient cleaning for use of 3-D printed objects in Cleanrooms. The results demonstrate that simple 3-D printed objects, such as wafer boxes or tweezers, are not notable contamination sources, and hence, are equally suitable for use in Cleanrooms as the commercial equivalents.

Kui Shan - One of the best experts on this subject based on the ideXlab platform.

  • coordinated demand controlled ventilation strategy for energy efficient operation in multi zone Cleanroom air conditioning systems
    Building and Environment, 2021
    Co-Authors: Chaoqun Zhuang, Kui Shan, Shengwei Wang
    Abstract:

    Abstract Cleanrooms can be 10–100 times as energy-intensive as typical office buildings. The causes of this are mainly high air change rates and counteraction (i.e. overcooling and reheating) processes in applications. Existing studies have addressed the design and control of outdoor and supply air ventilation systems separately without considering the interaction between them, which causes significant energy waste. This study therefore proposes a coordinated demand-controlled ventilation (CDCV) strategy to achieve energy-efficient operation in multi-zone Cleanroom air-conditioning systems, by coordinating operation between outdoor and supply ventilation systems. The Lorenz curve and Gini index are introduced to quantify the demand diversity of multiple zones, and degrees of overcooling and overdrying are used to quantify the mismatch between cooling supply and demand. Cleanrooms in a pharmaceutical factory located in Hong Kong, a humid sub-tropical city, are selected to test and validate the effectiveness of the proposed strategy. Test results show that the optimization of supply air volume can alleviate the mismatch between cooling supply and demand, as well as affect the optimal outdoor air ventilation mode. The proposed strategy can achieve up to 89.6% of reheating and 63.3% of overall energy savings.

  • probabilistic optimal design of Cleanroom air conditioning systems facilitating optimal ventilation control under uncertainties
    Applied Energy, 2019
    Co-Authors: Chaoqun Zhuang, Shengwei Wang, Kui Shan
    Abstract:

    Abstract Buildings with spaces requiring strict temperature and humidity controls, such as pharmaceutical Cleanrooms and semiconductor/microchip factories, have been growing very quickly in terms of total floor area and energy consumption. In such buildings, much of the energy is unnecessarily wasted due to the incoordination of system design and operation/control, especially under “off-design” and ever-changing ambient and load conditions. This paper, therefore, proposes a probabilistic optimal design method for Cleanroom air-conditioning systems facilitating optimal ventilation control under uncertainties. To consider the effects of asynchronous loads in different zones/spaces with reduced computation demand, a probabilistic diversity factor method is proposed which is a simplified method to quantify the effects of uncertainties of space load diversities in multiple zones/spaces using diversity factors. The proposed design method is implemented and validated in the design optimization of air-conditioning systems for implementing four different ventilation control strategies considering possible and uncertain off-design conditions. The energy and economic performance as well as service satisfaction of the air-conditioning systems are also evaluated and compared. Results show that the proposed design method can obtain the optimal air-conditioning systems with minimum life-cycle cost and superior satisfaction of service.

  • energy efficient design and control of Cleanroom environment control systems in subtropical regions a comparative analysis and on site validation
    Applied Energy, 2017
    Co-Authors: Kui Shan, Shengwei Wang
    Abstract:

    Abstract Compared with spaces air-conditioned for thermal comfort, Cleanrooms often have special requirements on dry bulb temperature, relative humidity and particle concentrations. It is a challenging task to achieve those requirements with minimum energy consumption, especially when different parameters interfere with each other. A significant amount of energy would be wasted if the system is not properly designed and controlled. This paper firstly provides an overview and a discussion on the essentials for design and control of Cleanroom air-conditioning systems. The existing systems and controls are categorized into three typical options and their performances are then analyzed based on different weather and load conditions. For new design, the “fully decoupled option” is the preferred option for humid sub-tropical regions. The analysis results are applied in a retrofit project for a pharmaceutical factory located in Hong Kong, a humid sub-tropical city, which employed the “interactive option”. This system is proposed to operate as a “partially decoupled option” in this project since such retrofit requires no modification on the existing hardware. The retrofitted system option has been on-site tested in mild weather condition, which provided 69.6% and 87.8% reductions of cooling and heating consumptions respectively. More comprehensive comparison tests are also conducted on a dynamic platform built on Matlab/Simulink.

Tengfang Xu - One of the best experts on this subject based on the ideXlab platform.

  • developing an innovative fan dry coil unit fdcu return system to improve energy efficiency of environmental control for mission critical Cleanrooms
    Energy and Buildings, 2015
    Co-Authors: Shih-cheng Hu, Tengfang Xu
    Abstract:

    Abstract Traditional wall-return re-circulation air systems with ceiling-supply and wall-return air grilles are fairly common in non-unidirectional airflow industrial Cleanrooms. Such re-circulation systems normally have longer airflow circulation pathways, which inherently induced higher airflow resistance, resulting in higher fan power demand per unit of airflow rate delivered. To overcome the airflow resistance, Fan Filter Units (FFUs) used in the traditional wall-returned re-circulation system are designed to operate with high external pressures, which also induce high negative pressures in supply air plenums (SAP). The negative pressures within SAP can increase the risks of infiltration of outdoor air and contaminants. A longer airflow pathway corresponds to a higher level of negativity of the air pressure inside the supply air plenum, thus inducing higher risks of cross-contamination. To overcome the above-mentioned drawbacks, a new re-circulation system using fan dry coil unit (FDCU) was proposed. This new system exhibits shorter air re-circulation paths while providing effective environmental controls (e.g., removal rate of 0.1 μm particle and temperature control) for a Cleanroom. In this study, experiments were conducted in a full-scale Cleanroom to investigate the energy performance of applying the innovative FDCU-return system, compared to a traditional wall-return system. Results showed that the FDCU-return system can increase energy efficiency and reduce the electric energy consumption by more than 4% compared to the wall-return system.

Richard C Linger - One of the best experts on this subject based on the ideXlab platform.

  • Cleanroom Software Engineering Reference
    2018
    Co-Authors: Richard C Linger, C J Trammell
    Abstract:

    Cleanroom software engineering is a theory-based team-oriented process for development and certification of high-reliability software systems under statistical quality control. A principal objective of the Cleanroom process is development of software that exhibits zero failures in use. The Cleanroom name is borrowed from hardware Cleanrooms, with their emphasis on rigorous engineering discipline and focus on defect prevention rather than defect removal. Cleanroom combines mathematically based methods of software specification, design, and correctness verification with statistical, usage-based testing to certify software fitness for use. Cleanroom projects have reported substantial gains in quality and productivity. This report defines the Cleanroom Software Engineering Reference Model, or CRM. The CRM is expressed in terms of a set of 14 Cleanroom processes and 20 work products. It is intended as a guide for Cleanroom project management and performance, process assessment and improvement, and technology transfer and adoption

  • Cleanroom software engineering developing software under statistical quality control
    Encyclopedia of Software Engineering, 2002
    Co-Authors: Harlan D. Mills, Richard C Linger
    Abstract:

    Cleanroom software engineering is a theory-based, team-oriented engineering process for developing and certifying very high quality software under statistical quality control. (The name “Cleanroom” was chosen in analogy to the precision engineering of hardware Cleanrooms.) Cleanroom software engineering methods include box structure specification and design, function-theoretic correctness verification, incremental development, and usage-based statistical testing for certification of software fitness for use. Cleanroom teams are organized into specification, development, and certification (testing) roles. The Cleanroom process originated in IBM in the mid-1980s to bring engineering rigor to software development. Cleanroom software engineering has been applied with excellent results in a variety of system developments, and continues to evolve as an engineering technology. Keywords: statistical quality control; software; Cleanroom management process; Cleanroom software development; verification; Cleanroom; certification; results

  • adopting Cleanroom software engineering with a phased approach
    Ibm Systems Journal, 1994
    Co-Authors: P A Hausler, Richard C Linger, C J Trammell
    Abstract:

    Cleanroom software engineering is a theory-based, team-oriented engineering process for developing very high quality software under statistical quality control. The Cleanroom process combines formal methods of object-based box structure specification and design, function-theoretic correctness verification, and statistical usage testing for reliability certification to produce software approaching zero defects. Management of the Cleanroom process is based on a life cycle of development and certification of a pipeline of user-function increments that accumulate into the final product. Teams in IBM and other organizations that use the process are achieving remarkable quality results with high productivity. A phased implementation of the Cleanroom process enables quality and productivity improvements with an increased control of change. An introductory implementation involves the application of Cleanroom principles without the full formality of the process; full implementation involves the comprehensive use of formal Cleanroom methods; and advanced implementation optimizes the process through additional formal methods, reuse, and continual improvement. The AOEXPERT/MVS™ project, the largest IBM Cleanroom effort to date, successfully applied an introductory level of implementation. This paper presents both the implementation strategy and the project results.

  • Cleanroom software engineering for zero defect software
    International Conference on Software Engineering, 1993
    Co-Authors: Richard C Linger
    Abstract:

    Cleanroom software engineering is a theory-based, team-oriented process for developing very high quality software under statistical control. Cleanroom combines formal methods of object-based box structure specification and design, function-theoretic correctness verification, and statistical usage testing for quality certification to produce software that has zero defects with high probability. The process of Cleanroom development and certification is carried out incrementally. Interface and design errors are rare because at each stage the harmonious operation of future increments at the next level of refinement is predefined by increments already in execution. The Cleanroom process is being successfully applied in IBM and other applications. Quality results from several Cleanroom projects are summarized. >