Development and Validation of Online Models With Parameter Estimation for a Building Zone With VAV System

Dynamic Systems and Control, Parts A and B ◽

10.1115/imece2004-59896 ◽

2004 ◽

Author(s):

Jin Wen ◽

Theodore F. Smith

Keyword(s):

Parameter Estimation ◽

Air Flow ◽

Hvac Systems ◽

Test Facility ◽

Prediction Errors ◽

Commercial Building ◽

Variable Air Volume ◽

Online System ◽

System Models ◽

Validation Tests

The energy consumption by building heating, ventilating, and air conditioning (HVAC) systems has evoked more attention for energy efficient HVAC control and operation. Application of advanced control and operation strategies requires robust online system models. In this research, online models with parameter estimation for a building zone with variable air volume (VAV) system, which is one of the most common HVAC systems, are developed and validated using experimental data. Building zone temperature and VAV entering air flow are modeled based on physical rules and using only the measurements that are commonly available in a commercial building. Different series of validation tests were performed in a real-building test facility to examine the prediction accuracies for system outputs. Using the online system models with parameter estimation, the prediction errors for all the validation tests are less than 0.5°F for temperature outputs, and less than 50 ft3/min for air flow outputs. The online models can be further used for local and supervisory control, as well as fault detection applications.

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Development and Validation of Online Parameter Estimation for HVAC Systems

Journal of Solar Energy Engineering ◽

10.1115/1.1591802 ◽

2003 ◽

Vol 125 (3) ◽

pp. 324-330 ◽

Cited By ~ 4

Author(s):

Jin Wen ◽

Theodore F. Smith

Keyword(s):

Energy Efficiency ◽

Parameter Estimation ◽

Hvac Systems ◽

Recursive Least Squares ◽

Volume Discharge ◽

Thermal Loads ◽

Variable Air Volume ◽

Improve Energy Efficiency ◽

System Parameters ◽

Air Volume

Improving the energy efficiency of buildings by examining their heating, ventilating, and air-conditioning (HVAC) systems represents an opportunity. To improve energy efficiency, to increase occupant comfort, and to provide better system operation and control algorithms for these systems, online estimation of system parameters, including system thermophysical parameters and thermal loads, is desirable. Several reported studies have presented simulation results and assumed that the thermal loads are known. A difficulty in HVAC system parameter estimation is that most HVAC systems are nonlinear, have multiple and time varying parameters, and require an estimate of the thermal loads for a building zone. In this study, building zones and variable-air-volume units are modeled. The system parameters including the thermal loads are estimated using the recursive-least-squares method with a variable forgetting factor. The sensitivity of the estimation results to different factors is examined. The estimated parameters are used to predict the zone and variable-air-volume-discharge-air temperatures. Several experiments are used to validate the prediction results. The comparisons show good agreement between the experiments and the prediction results.

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Development and Validation of Online Parameter Estimation for HVAC Systems

Heat Transfer, Volume 6 ◽

10.1115/imece2002-32432 ◽

2002 ◽

Cited By ~ 1

Author(s):

Jin Wen ◽

Theodore F. Smith

Keyword(s):

Parameter Estimation ◽

Thermal Load ◽

Least Squares Method ◽

Hvac Systems ◽

Recursive Least Squares ◽

Thermal Loads ◽

Variable Air Volume ◽

Improve Energy Efficiency ◽

System Parameters ◽

Occupant Comfort

Heating, ventilating, and air-conditioning systems of buildings consume nearly 50 percent of the world’s energy. To improve energy efficiency, to increase occupant comfort, and to provide better system operation and control for these systems, online estimation of system parameters, including system thermophysical parameters and thermal loads, is desirable. Several reported studies have presented simulation results and assumed that the thermal loads are known. A difficulty in HVAC system parameter estimation is that most HVAC systems are nonlinear, have multiple and time varying parameters, and require an estimate of the thermal load for a building zone. In this study, the building zone and variable-air-volume unit are modeled. The system parameters including the thermal load are estimated using the recursive-least-squares method with variable forgetting factor. The sensitivity of the estimation results to different factors is examined. Different experiments are used to validate the estimation results. The comparisons between the experiments and the estimation results show good agreement.

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Mass Air Flow Test Facility

10.4271/820324 ◽

1982 ◽

Author(s):

Victor J. Nowak ◽

Allan L. Oberstadt

Keyword(s):

Air Flow ◽

Test Facility ◽

Flow Test

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Evaluation of frequency regulation provision by commercial building HVAC systems

2017 13th IEEE Conference on Automation Science and Engineering (CASE) ◽

10.1109/coase.2017.8256215 ◽

2017 ◽

Author(s):

Yang Liu ◽

Nanpeng Yu ◽

Jie Shi ◽

Bing Dong ◽

Wei Ren ◽

...

Keyword(s):

Hvac Systems ◽

Frequency Regulation ◽

Commercial Building

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Dynamics of a Dual-Clutch Gearbox System: Analysis and Experimental Validation

Journal of the American Helicopter Society ◽

10.4050/jahs.58.012004 ◽

2013 ◽

Vol 58 (1) ◽

pp. 17-28 ◽

Cited By ~ 7

Author(s):

David G. Lewicki ◽

Hans DeSmidt ◽

Edward C. Smith ◽

Steven W. Bauman

Keyword(s):

Experimental Validation ◽

System Analysis ◽

Friction Model ◽

Test Facility ◽

Motor Speed ◽

Dynamic Simulations ◽

Stick Slip ◽

Dry Clutch ◽

Six Degree Of Freedom ◽

Validation Tests

Dynamic simulations and experimental validation tests were performed on a two-stage, two-speed gearbox. The gearbox was driven by two electromagnetic motors and had two electromagnetic, multidisk clutches to control output speed. A dynamic model of the system was created, which included a DC electric motor with proportional–integral–derivative speed control, a two-speed gearbox with dual electromagnetically actuated clutches, and an eddy current dynamometer. A six-degree-of-freedom model of the gearbox accounted for the system torsional dynamics and included gear, clutch, shaft, and load inertias as well as shaft flexibilities and a dry clutch stick-slip friction model. Experimental validation tests were performed on the gearbox in the NASA Glenn gear noise test facility. Gearbox output speed and torque as well as drive motor speed and current were compared to those from the analytical predictions. The experiments correlate very well with the predictions, thus validating the dynamic simulation methodologies.

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