Mechanical Engineering Commons^™

Effect Of The Distribution Of Faults And Operating Conditions On Afdd Performance Evaluations, David Yuill, James E. Braun

David Yuill

Validation Of A Fault-Modeling Equipped Vapor Compression System Model Using A Fault Detection And Diagnostics Evaluation Tool, David P. Yuill, Howard Cheung, James E. Braun

David Yuill

A methodology for evaluating the performance of fault detection and diagnostics (FDD) tools for unitary air- conditioners has been developed (Yuill and Braun 2013). The methodology uses laboratory measurements of systems with and without faults to test FDD tools’ effectiveness. A gray box modeling method capable of modeling systems with faults was developed by Cheung and Braun (2013a and 2013b) to provide input data, as an alternative to using laboratory data that had been collected. The simulation method was validated by direct comparison with experimental data, but a comparison of FDD evaluation results provides a more direct and useful validation …

Evaluating The Performance Of Fault Detection And Diagnostics Protocols Applied To Air-Cooled Unitary Air-Conditioning Equipment, David P. Yuill, James E. Braun

David Yuill

Fault detection and diagnostics (FDD) tools are increasingly being applied to air-cooled unitary air-conditioning systems. However, it is not known how well these tools work because there is no standard method of measuring or evaluating the performance of FDD. In the current paper the authors describe the common faults that FDD is applied to in unitary systems, and propose a method of evaluating the performance of FDD protocols. The method involves feeding measurement data through a candidate protocol and collecting and organizing the responses based upon the fault’s impacts on performance. A library of faulted and unfaulted measurement data has …

Evaluating Fault Detection And Diagnostics Protocols Applied To Air-Cooled Vapor Compression Air-Conditioners, David P. Yuill, James E. Braun

David Yuill

Fault detection and diagnostics (FDD) tools are being increasingly applied in air-conditioning systems. There are many different protocols used in these FDD tools, so an important question to ask is: how well do the protocols work? This paper describes the ongoing development of the first standardized method of evaluation for FDD protocols applied to air-cooled vapor compression air-conditioning systems. The general approach is to feed a library of data – including temperatures, pressures, and humidity – to a candidate FDD protocol, and observe the responses of the protocol. The library includes data from units operating with no fault or with …

Performance Comparison Of Control Methods For Tankless Water Heaters, David P. Yuill, Andrew H. Coward, Gregor P. Henze

David Yuill

Tankless water heaters (TWH) have several advantages and disadvantages when compared with storage water heaters. One disadvantage is that the outlet temperature of the water is difficult to control. To address this problem, the authors apply seven different control approaches and con- duct experiments to test the effectiveness of each approach. The experiments are carried out on a commercially available electric TWH, using a test method and apparatus developed by the authors. The seven approaches include various configurations of feedback or feed-forward con- trol, or both. One fairly simple approach devised in this project combines feedback and feed-forward control. This …

Development Of A Model Predictive Controller For Tankless Water Heaters, Gregor P. Henze, David P. Yuill, Andrew H. Coward

David Yuill

This paper describes the development of a novel approach to temperature control of tankless water heaters (TWHs). Conventional methods of controlling TWHs typically allow a high degree of error in the outlet water temperature when subjected to disturbances in flow rate or inlet water temperature. Poor control affects comfort, safety, and energy consumption associ- ated with TWHs. The novel control approach presented here uses model predictive control (MPC) to minimize the outlet temperature error. A dynamic heat transfer model of an electric TWH is developed and validated and used within a MPC-based controller. The controller is interfaced to a physical …

Measurement And Analysis Of Vitiation Of Secondary Air In Air Distribution Systems (Rp-1276), David P. Yuill, Grenville K. Yuill, Andrew H. Coward

David Yuill

Development Of A Fan Airflow Station For Airflow Control In Vav Systems, David Yuill, Nathan Redmann, Mingsheng Liu

David Yuill

A fan airflow station has been developed by the authors. This station is used to determine fan airflow using fan speed and fan head as inputs. These inputs can be measured accurately in variable air volume (VAV) systems, so they can be used as a cost-effective control monitoring method for heating, ventilation and air conditioning (HVAC) systems. Theoretical models have been developed for the flow station using both second and third order relationships between the airflow and the inputs. The theoretical model has been experimentally tested and excellent agreement between the model and the experimental values was found. The second …