[首頁] [履歷] [研究] [著作摘要]
[地址] [學歷] [工作經歷] [參與計畫] [著作]


著作表

  1. Analysis of Optimum Ventilation Controls in Different Geographic Locations
  2. Variable Air Volume Ventilation Control Strategies Analyzed in Six Climate Zones
  3. Analytical Determination of Duct Fitting Loss Coefficients
  4. Field Testing of Advanced Ventilation Controls for Variable Air Volume Systems
  5. Air Handling Unit Direct Digital Control System Retrofit to Provide Acceptable Indoor Air Quality and Global Energy Optimization
  6. Optimum Ventilation Control for Variable-Air-Volume Systems
  7. Applications of Carbon Dioxide Measurements for Ventilation Controls
  8. Using Carbon Dioxide Measurements to Determine Occupancy for Ventilation Controls
  9. Simulation Results and Analysis of Eight Ventilation Control Strategies in VAV Systems
  10. Ultrasonic Humidification; System Integration, Energy, and Indoor Air Quality Engineering Issues
  11. Optimized Supply Air Temperature (SAT) in Variable-Air-Volume (VAV) Systems
  12. Close Coupled Ductwork Fitting Pressure Drop
  13. Derivation of Equations Necessary for Primary Airflow Redistribution in VAV Systems to Reduce Outdoor Air Intake While Meeting Ventilation Requirements
  14. A Generalized Multiple Spaces Equation to Accommodate Any Mix of Close-off and Fan-Powered VAV Boxes
  15. 建築外殼總熱傳值 OTTV 應用於台灣地區之分析
  16. 建築外殼空調負荷值之分析
  17. 建築空調負荷省能指標之研究
  18. The Analysis of Enthalpy Control Strategies and Its Application in Hot and Humid Climates

著作摘要

  1. Analysis of Optimum Ventilation Controls in Different Geographic Locations
    by Yu-Pei Ke and S. A. Mumma
    Submitted to Environment International

    This paper presents four ventilation controls for variable-air-volume (VAV) systems. Their annual power demand and indoor air quality (IAQ) simulation results for an academic building as if it were situated in each of six geographic locations are analyzed. The first ventilation control satisfies the minimum system outdoor air (OA) requirement accounting for the diversity of ventilation-thermal load ratio of each zone. The other three controls employ optimization techniques on one or both of two air-side system variables: primary airflow rate and supply air temperature (SAT). From an energy perspective, ventilation controls using the optimization techniques minimize the operating energy use of heating, ventilating, and air-conditioning (HVAC) systems. The savings from optimized primary airflow and/or SAT varies in different geographic locations (or climatic zones). This paper provides clear comparisons between optimized ventilation controls in different climatic zones. Compared with the non-optimization ventilation control, the best control, optimizing both variables, saves up to 14% power in mild weather, while reducing power demand only 2.1% in hot-humid weather.


  2. Variable Air Volume Ventilation Control Strategies Analyzed in Six Climate Zones
    by Yu-Pei Ke and S. A. Mumma
    in International Journal of Energy Research, vol. 23, n. 5, pp. 371-387, 1999.
    (EI, SCI, ISI Impact Factor of 1997: 0.209)

    This paper presents eight ventilation control strategies and their annual energy and indoor air quality simulation results for an academic building as if it were situated in each of six geographic locations. The results show that without tempering at the terminal boxes, no ventilation strategy could satisfy the outdoor air requirements when the thermal loads are low, and the fixed outdoor air percentage method is the worst one. From an economic perspective, strategies using optimization techniques minimize the operation energy demand and consumption. Supply air temperature and primary airflow rate are the two proper optimizable parameters on the air side of heating, ventilating, and air-conditioning systems. In addition to control schemes, geographic locations or weather patterns verify the benefits of optimization. Generally, a mild-dry climate signifies the advantages of the SAT reset and encourages the primary airflow optimization. Inversely, hot-humid weather minimizes the benefits.


  3. Analytical Determination of Duct Fitting Loss Coefficients
    by S. A. Mumma, T. A. Mahank, and Yu-Pei Ke
    in Applied Energy, vol. 61, n. 4, pp. 229-247, 1998. (EI)

    Loss coefficient data for 9 ductwork fittings were generated utilizing a commercially available Computational Fluid Dynamics (CFD) code. A total of 159 unique coefficients were generated for the various flow and geometry conditions. The computer code was used to produce pressure field data necessary to compute the loss coefficients, as well as to produce flowfield and static pressure plots that offer insight into the physics of the flow field.
    The agreements between the published experimental and representative computational results were well within the 15% error bounds, with 2 notable exceptions. The exceptions were for the round die-stamped smooth radius and the round 5-gore radius elbows, where the loss coefficients obtained computationally were insensitive to diameter change with r/D constant at 1.5. The reason for the differences between the computational and published results is shown to be due to absolute roughness differences. The agreement has led to the conclusion that computational techniques could be accurately utilized to verify and expand duct fitting databases.


  4. Field Testing of Advanced Ventilation Controls for Variable Air Volume Systems
    by S. A. Mumma and Yu-Pei Ke
    in Environment International, vol. 24, n. 4, pp. 439-450, 1998.
    (EI, SCI, ISI Impact Factor of 1997: 0.746)

    Results from the experimental phase of a much larger research project are presented for three promising ventilation controls capable of meeting the ventilation requirements of ANSI/ASHRAE Standard 62-1989 with low energy use. Each control dynamically adjusted the outdoor air (OA) requirement based upon occupancy and measured building zone loads. Credit for unvitiated air from overventilated spaces was also taken in each control. Controls 2 and 3 used primary airflow rate as an optimization variable to decrease the required OA flow rate, thus reducing the energy needed to condition OA. The supply air temperature in control 2 was a constant, but was an additional optimization variable in control 3.

    The three ventilation controls were achieved by the simulation/optimization algorithms resident in a stand alone personal computer (PC) on site. A total of twenty-four days of performance data were collected. Typical day data sets for each control are presented in some detail. The objective of the experimental phase was to verify the reliability of the simulation/optimization algorithms resident in the on site PC. That objective was met for the each of the three controls since excellent agreement was found between the measured data and the control algorithm predictions.


  5. Air Handling Unit Direct Digital Control System Retrofit to Provide Acceptable Indoor Air Quality and Global Energy Optimization
    by S. P Sevigny, Yu-Pei Ke, S. A Mumma, and D. Stanke
    in Energy Engineering, vol. 94, n. 5, pp. 24-43, 1997. (EI)

    The project objective was to control outdoor ventilation airflow and distribution so that ASHRAE Standard 62-1989 was satisfied, while minimizing the impact of energy utilization. The base system Direct Digital Controls (DDC) are application specific, with insufficient custom programming capacity to meet the project objective by themselves. Three complex control schemes were installed. In all cases the concept was to continually reset the Outdoor Air (OA) fraction aspirated into the Air-Handling Unit (AHU) as necessary to satisfy ASHRAE Standard 62-1989. A personal computer based system, independent from the DDC controls, was used to collect data, perform the calculations, and send back new control settings.


  6. Optimum Ventilation Control for Variable-Air-Volume Systems
    by Yu-Pei Ke
    Doctoral Thesis, The Pennsylvania State University, USA, August 1997.

    Based upon the perception that the world energy supply is bounded, building mechanical system engineers have taken many measures to reduce energy consumption since the 1970's. Among the measures was a significant reduction in the ventilation air provided to building occupants. As a result, a host of building-induced illnesses surfaced. In response, The American Society of Heating, Refrigerating, and Air-conditioning Engineers developed the ANSI/ASHRAE Standard 62-1989 "Ventilation for Acceptable Indoor Air Quality," which set a ventilation rate per person that was energy intensive. Ever since, engineers and researchers have been seeking the best ways to provide acceptable indoor air quality (IAQ) with minimal energy consumption.

    This thesis research provides a solution to ameliorate the conflict between energy use and acceptable IAQ in buildings served with variable-air-volume mechanical systems. Eight ventilation controls were investigated, and the resultant quantitative measure of IAQ and energy consumption documented. Several of the controls employed optimization techniques to achieve the desired results.

    This research consists of two major portions, an analytical portion and an experimental field evaluation portion. In both the analytical and experimental portions, a library building close to Harrisburg, Pennsylvania, was used for evaluation. Detailed models of the building and its mechanical systems were developed. On an hourly basis for an entire year, the models were used to simulate the building and its systems located in six different geographic locations and operating under each of the eight ventilation controls. Three of the best controls were implemented into the library building and data collected under various weather conditions to confirm the analytical predictions.

    The analytical simulations verified the necessity of local tempering to ensure adequate outdoor air for a zone. The simulations also revealed that the best ventilation control, which simultaneously optimizes primary airflow and supply air temperature, results in the minimum energy consumption while providing acceptable IAQ. The benefits of the best ventilation controls vary with geographic locations (or climatic conditions). In general, mild weather signifies the energy savings from the supply air temperature optimization. The reduction in the power demand is up to 15% in Los Angeles. Cold weather is good for primary airflow optimization. The reduction in the power demand is up to 7.9% in Chicago. Conversely, hot-humid weather, such in Miami, flattens the variations between different controls. In addition, the field tests confirmed the reliability of the simulation work and demonstrated the transformation of the simulation code to optimization and control software applied to a real system. Copyright © 1997 Yu-Pei Ke


  7. Applications of Carbon Dioxide Measurements for Ventilation Controls
    by Yu-Pei Ke
    Master Thesis, The Pennsylvania State University, USA, August 1997.

    This research, first, proposed a new method to determine the dynamic zonal occupancy for ventilation control based upon measured carbon dioxide (CO2) concentrations in the supply and return airflows. The central thesis of this proposed transient method was that a fixed CO2 threshold based upon occupancy alone is not possible under the current proposed BSR/ASHRAE Standard 62-1989R. Rather the actual dynamic occupancy headcount must be known since the ventilation requirements consist of two parts, the building component and the occupancy component. The result is that the CO2 threshold must constantly be changed in time with occupancy.

    Based on the known occupancy, this research then developed equations to determine the total unused outdoor air (OA) flow rate in the discharge airflow. If the CO2 threshold is fixed, the quantity of unused OA can be determined from CO2 concentration in the return airflow; this is invalid for changing CO2 thresholds that differ from zone to zone. The scheme developed in this research solved this difficulty and determined the unused OA flow rate explicitly. Combined with the transient occupancy-based ventilation scheme, this algorithm is useful for real-time on-line ventilation control and system optimization.

    Finally, this research employed simulation results for well-mixed office and conference rooms as the basis for comparison of the proposed transient occupancy-based ventilation with two other accepted methods: the CO2-based ventilation and the constant airflow ventilation. The simulation results show that calculated occupancy from the transient equation follows the actual occupancy precisely with a time lag equal to the measurement scan interval. With the precise occupancy information, the mechanical system can provide the exact ventilation airflow required by standards. From a ventilation perspective, the transient occupancy-based ventilation scheme is better than the conventional CO2-based ventilation, and without an energy penalty. Copyright © 1997 Yu-Pei Ke


  8. Using Carbon Dioxide Measurements to Determine Occupancy for Ventilation Controls
    by Yu-Pei Ke and S. A. Mumma
    in ASHRAE Transactions, vol. 103, pt. 2, pp. 365-374, 1997. (EI)

    This paper proposes a new method to determine the dynamic zonal occupancy for ventilation control based upon measured carbon dioxide (CO2) concentrations in the supply and return air. The central thesis of this proposed transient method is that a fixed CO2 threshold based upon occupancy alone is not possible under the current proposed BSR/ASHRAE Standard 62-1989R. Rather the actual dynamic occupancy headcount must be known since the ventilation requirements consist of two parts, the building component and the occupancy component. The result is that the CO2 threshold must constantly be changed in time with occupancy. This paper employs simulation results for well-mixed office and conference rooms as the basis for comparison of the proposed transient occupancy-based ventilation with two other accepted methods: the CO2-based ventilation and the constant airflow ventilation. The simulation results show that calculated occupancy from the transient equation follows the actual occupancy precisely with a time lag equal to the measurement scan interval. With the precise occupancy information, the mechanical system can provide the exact ventilation airflow required by standards. From a ventilation perspective, the transient occupancy-based ventilation scheme is better than the conventional CO2-based ventilation, and without an energy penalty. Furthermore, this scheme is useful for real-time on-line ventilation control and system optimization. Copyright © 1997 ASHRAE, Inc.


  9. Simulation Results and Analysis of Eight Ventilation Control Strategies in VAV Systems
    by Yu-Pei Ke, S. A. Mumma, and D. Stanke
    in ASHRAE Transactions, vol. 103, pt. 2, pp. 381-392, 1997. (EI)

    This paper presents eight ventilation control strategies and their annual energy and indoor air quality simulation results for an academic building. The results show that without tempering at the terminal boxes, no ventilation strategy could satisfy the outdoor air requirements when the thermal loads are low, and the fixed outdoor air percentage method is the worst one. From an economic perspective, strategies using optimization techniques minimize the operation energy demand and consumption. Supply air temperature and primary airflow rate are the two proper optimizable parameters on the air side of heating, ventilating, and air-conditioning systems. Copyright © 1997 ASHRAE, Inc.


  10. Ultrasonic Humidification; System Integration, Energy, and Indoor Air Quality Engineering Issues
    by S. A. Mumma, Yu-Pei Ke, and S. P Sevigny
    in ASHRAE Transactions, vol. 103, pt. 2, pp. 894-905, 1997. (EI)

    Ultrasonic humidification has become increasingly popular for both indoor air quality and energy related reasons. The central thrust of this paper is to explore these 2 reasons in depth. Application of ultrasonic humidification, however, raises a number of design and operational issues that are not important with steam humidification. The 3 main issues, also emphasized in this paper, are: heating coil requirements, supply air temperature control sensor placement, and the impact of the size and number of stages of humidification on supply air temperature control hunting. Finally, the analytical tools, currently missing from both private and large public domain energy analysis software, are developed in the paper and applied to a specific academic library building located in central Pennsylvania. Copyright © 1997 ASHRAE, Inc.


  11. Optimized Supply Air Temperature (SAT) in Variable-Air-Volume (VAV) Systems
    by Yu-Pei Ke and S. A. Mumma
    in Energy--The International Journal, vol. 22, n. 6, pp. 601-614, 1997.
    (EI, SCI, ISI Impact Factor of 1997: 0.317)

    A criterion, based on optimization principles, for determining the SAT setpoint in VAV systems is presented. It is generally accepted that conventional SAT reset controls (SATRC), bounded by either space humidity or ductwork size, will save cooling and/or heating energy. However, the ventilation consequences and penalty resulting from increased fan power have generally been overlooked. Ventilation is impacted since changes in the SAT setpoint change the primary airflow rate and the operation of economizer cycles, i.e. the distribution of fresh outdoor air (OA). These changes may result in extra energy demand and ventilation inefficiency if the reset criterion is not appropriate. This optimization concept simultaneously reduces energy consumption and meets ventilation requirements. Simulation results illustrate that the use of the optimized SATRC saves more energy than a conventional one. Copyright © 1997 Elsevier Science Ltd.


  12. Close Coupled Ductwork Fitting Pressure Drop
    by S. A. Mumma, T. A. Mahank, and Yu-Pei Ke
    in International Journal of Heating, Ventilating, Air-Conditioning and Refrigerating Research, vol. 3, n. 2, pp. 158-177, 1997. (EI)

    The impact of close coupled ductwork fittings on system pressure drop is the thrust of this paper. The configuration was for a college library building. The following research tools were employed: computational fluid dynamic (CFD) analysis, scaled fitting and arrangement testing in the laboratory, and full-scale arrangement field testing. The research revealed that close coupling of fittings can be either complementary or detrimental, depending on the specific circumstance. For the fittings investigated, close coupling resulted in an approximately 27% higher pressure loss than predicted using conventional procedures. Copyright © 1997 ASHRAE, Inc.

  13. Derivation of Equations Necessary for Primary Airflow Redistribution in VAV Systems to Reduce Outdoor Air Intake While Meeting Ventilation Requirements
    by Yu-Pei Ke and S. A. Mumma
    in International Journal of Heating, Ventilating, Air-Conditioning and Refrigerating Research, vol. 3, n. 1, pp. 3-18, 1997. (EI)

    The multiple spaces equation of ASHRAE Standard 62-1989 makes it possible to bring in a smaller fraction of outdoor air than that dictated by the critical space. This paper develops an analytical proof that increasing the primary airflow rate to the critical space reduces the outdoor airflow rate required to meet ventilation requirements. For systems employing fan-powered boxes, where more than one box is critical, a systematic procedure for incrementally increasing the primary air is currently required. Also presented are equations necessary to undertake such a systematic procedure of incrementally increasing the primary air for situations typically encountered in the operation of fan-powered variable-air-volume systems. Copyright © 1997 ASHRAE, Inc.


  14. A Generalized Multiple Spaces Equation to Accommodate Any Mix of Close-off and Fan-Powered VAV Boxes
    by Yu-Pei Ke and S. A. Mumma
    in ASHRAE Transactions, vol. 102, pt. 1, pp. 183-192, 1996. (EI)

    The central trust of this paper will be to derive a generalized form of the multiple spaces Equation 6-1 which appears in ASHRAE Standard 62-1989 (the Standard). The multiple spaces equation currently in the Standard is for single duct systems such as VAV systems using close-off boxes only. In such systems all recirculated air is assumed to mix with the outdoor air at a central air handling unit. Since many VAV systems designed and installed today employ fan-powered boxes, there was a sense of urgency associated with deriving the generalization presented here. The new generalized multiple spaces equation extends the applicability of the multiple spaces concept to include air distribution systems which can recirculate a portion of the return air from well-mixed return plenums directly back into the fan-powered terminal units for mixing with primary supply air. Further, the work illustrates that VAV systems employing fan-powered boxes may often comply with the Standard while using less outdoor air than would be required in a close-off VAV system. Copyright © 1996 ASHRAE, Inc.


  15. 建築外殼總熱傳值 OTTV 應用於台灣地區之分析
    楊冠雄、柯佑沛
    中華民國第十四屆全國力學會議論文集,1445-1452頁,民國79年12月。

    本文從動態 (Dynamic) 熱傳理論出發,並配合臺灣地區的平均氣象 年資料 (Average Year Weather Data),來探討廣受東南亞國家採用 之建築省能基準 OTTV (Overall Thermal Transfer Value)。本文計 算出臺灣地區採用 OTTV 公式時各參數之合宜值,這些修正後的數值 確切地反應了臺灣地區的氣候狀況。以此算出之建築外殼總熱傳值 OTTV 能真正表達建築物外殼的總熱得率,因此可以其作為空調負荷 省能指標。此外,利用直交表計算出臺灣地區的 OTTV 理論平均值, 與 46 棟具代表性之既存建築實際值加以比較,兩者極為接近。 以平均值和標準差可預測臺灣地區建築物之 OTTV 分布情形,此結果 可供訂立標準值之參考。最後,以此 46 棟實際建築為樣本,應用迴 歸分析,將 OTTV公式予以簡化,以便易於計算而又不失精確。


  16. 建築外殼空調負荷值之分析
    楊冠雄、柯佑沛
    中國機械工程師學會第七屆年會論文集,443-454頁,民國79年11月。

    本文從動態(Dynamic)熱傳理論出發,並配合臺灣地區的平均氣象年資料 (Average Year Weather Data),新創一建築外殼省能基準 ECLV (Envelope Cooling Load Value),作為空調負荷省能指標。此外,利用直交表計算出 其在臺灣地區的理論值,與 46 棟具代表性之既存建築實際值,兩者加以比 較。本文所提出新的建築外殼省能指標 ECLV,在理論基礎上比 ASHRAE Standard 90.75 之 OTTV 指標更完備,可取代 OTTV 作為建築外殼省能基準。


  17. 建築空調負荷省能指標之研究
    柯佑沛
    國立中山大學機械工程研究所碩士論文,民國79年6月。

    本文從動態 (Dynamic) 熱傳理論出發,並配合臺灣地區的平均氣象年資料 (Average Year Weather Data),來探討廣受東南亞國家採用之建築省能基 準 OTTV (Overall Thermal Transfer Va1ue),計算出臺灣地區採用 OTTV 公式時各參數之合宜值。並進一步延續原本是熱得指標的 OTTV 計算方式, 新創另一建築外殼省能基準 ECLV (Envelope Cooling Load Value),作為 空調負荷省能指標,此外,並引入日本 PAL (Perimeter Annual Load) 的 觀念,以林氏簡算法計算其值。本文將此三種指標,利用亙交表計算出三者 在臺灣地區的理論值,與 46 棟具代表性之既存建築實際值。兩者加以比較 ,以供基準值訂定之參考。

    三種指標中,以 PAL 所考慮的最為周詳,採用其作為建築的省能指標最為準 確。但 OTTV 和 ECLV 仍有計算方便上的優點,且相富適合作為小型住宅的 能源指標。本文所提出新的建築外殼省能指標ECLV,在理論基礎上比 OTTV 更完備,可取代  OTTV 作為建築外殼省能基準。然而,基于 OTTV 和 ECLV 本身的簡化模式特性,若要採用其為省能指標,最好只應用 于住宅建築。


  18. The Analysis of Enthalpy Control Strategies and Its Application in Hot and Humid Climates
    by Kuan-Hsiung Yang, R. L. Hwang, and Yu-Pei Ke
    in Proceeding of Building Simulation '89, International Building Performance Simulation Association, Canada, pp. 347-354, June 1989.

    Air enthalpy control strategy, or often known as free cooling, has been very effective in conserving building air-conditioning power consumption in moderate climatic areas. However, it stands for a challenge in hot and humid areas, such as in Taiwan, where outdoor air enthalpies are constantly high.

    Three control schemes, namely, temperature control (economizer, or T-control) enthalpy control (H-control), and the modified temperature control (MT-control), were studied in this paper.

    The MT-control method was actually applied on a full-scale energy test house for experimental investigation. Night ventilation in scavenging residual heat gain through building envelope had successfully introduced lower indoor temperature as expected in a typical April day.

    The simulation result of their annual performance was also validated that enthalpy control strategies have quite limited application potential in hot and humid areas, especially in the summer when cooling is most needed.

歡迎來信: ypke@nkfust.edu.tw construction日期: 90.12.3

[地址] [學歷] [工作經歷] [參與計畫] [著作]
[首頁] [履歷] [研究] [著作摘要]