An Innovation-Based Methodology for HVAC System Fault Detection

1985 ◽  
Vol 107 (4) ◽  
pp. 284-289 ◽  
Author(s):  
P. B. Usoro ◽  
I. C. Schick ◽  
S. Negahdaripour

Although Energy Management and Control Systems (EMCS) have since the early 1970’s contributed significantly to the reduction (20-40 percent) of energy use in buildings without sacrificing occupants’ comfort, their full capabilities have not been completely realized. This is in part due to their inability to quickly detect and compensate for failures in the Heating, Ventilation and Air Conditioning (HVAC) system. In fact, no matter how good the control scheme for the HVAC system might be, the presence of undetected faults can completely offset any expected savings. This paper presents a methodology for detecting faults in an HVAC system using a nonlinear mathematical model and an extended Kalman filter. The technique was implemented in a computer program and successfully used to detect “planted” faults in simulations of the air handler unit of an HVAC system. Test results are presented to demonstrate the effectiveness of the methodology.

Author(s):  
Patrick Opdenbosch ◽  
Nader Sadegh ◽  
Wayne J. Book

This paper explores the dynamic modeling of a novel two stage bidirectional poppet valve and proposes a control scheme that uses a Nodal Link Perceptron Network (NLPN). The dynamic nonlinear mathematical model of this Electro-Hydraulic Control Valve (EHCV) is based on the analysis of the interactions among its mechanical, hydraulic, and electromagnetic subsystems. A discussion on experimental approaches to determine the model parameters is included along with model validation results. Finally, the control scheme is developed by proposing that the states of the EHCV follow a set of desired states, which are calculated based upon the desired valve flow conductance coefficient KV. A simulation is presented at the end to verify the proposed control scheme.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 400 ◽  
Author(s):  
Zelin Nie ◽  
Feng Gao ◽  
Chao-Bo Yan

Reducing the energy consumption of the heating, ventilation, and air conditioning (HVAC) systems while ensuring users’ comfort is of both academic and practical significance. However, the-state-of-the-art of the optimization model of the HVAC system is that either the thermal dynamic model is simplified as a linear model, or the optimization model of the HVAC system is single-timescale, which leads to heavy computation burden. To balance the practicality and the overhead of computation, in this paper, a multi-timescale bilinear model of HVAC systems is proposed. To guarantee the consistency of models in different timescales, the fast timescale model is built first with a bilinear form, and then the slow timescale model is induced from the fast one, specifically, with a bilinear-like form. After a simplified replacement made for the bilinear-like part, this problem can be solved by a convexification method. Extensive numerical experiments have been conducted to validate the effectiveness of this model.


Author(s):  
Christian Kunkel ◽  
Jan Werner ◽  
Daniel Franke ◽  
Heinz-Peter Schiffer ◽  
Fabian Wartzek ◽  
...  

Abstract With the well-known Transonic Compressor Darmstadt (TCD) in operation since 1994, profound knowledge in designing and operating a sophisticated test-rig is available at the Institute of Gas Turbines and Aerospace Propulsion of TU Darmstadt. During this period, TCD has been subject to a vast number of redesigns within different measurement campaigns (see [1], [2], [3], [4], [5], [6], [7], [8]). To expand the capabilities and ensure a sustainable process of compressor research, a new test facility was designed and built by the institute. The new test rig Transonic Compressor Darmstadt 2 (TCD2) features increased power for higher pressure ratios and higher mass-flow, a state of the art control system, increased flexibility towards different compressor geometries and modern data acquisition hardware and software. Following the successful commissioning of the test-rig in March 2018, a first measurement campaign has been conducted. Early test results regarding aerodynamic performance and aeroelastic effects of the test compressor are presented together with a detailed overview of test-rig infrastructure and control systems as well as the test compressor and the measurement hardware.


Author(s):  
Salam Ibrahim Khather

The most important components of the distributed generation frameworks is the GTIs which is an interface amidst the utility and the source of energy. The recent years have seen an increased interest in the design and usage of GTIs due to its smaller weight and size, low cost and higher efficiency. But the problem of leakage currents in the transformerless inverter that is dependant on its topology and control scheme needs to be looked into carefully. Also, the high performance of the GTI requires a stringent control and various control systems are being developed and applied to the GTIs. This paper reviews the various topologies that are classified based on the attributes of the leakage current and the method of decoupling. Further it reviews and compares the different control techniques applied to the GTIs with respect to the frame of reference, controller, modulation technique and the control parameters considered.


2021 ◽  
Vol 283 ◽  
pp. 01051
Author(s):  
Xiaolong Ruan ◽  
Yisong Yin

With the continuous growth of my country's economy and the continuous improvement of the people's economic level, the demand for the design of heating, ventilation and air conditioning systems has also increased. The HVAC system is very important in the building environment. When optimizing the relevant design, it is necessary to always consider the design details of the HVAC system and adjust the integrity of the design, especially to take preventive measures in areas where noise and vibration may occur to avoid heating serious problems caused by noise and general vibration when the communication system is running. This article outlines how to avoid and control common noise and vibration problems when designing HVAC projects.


1988 ◽  
Author(s):  
F. William Payne ◽  
John J. McGowan

2021 ◽  
Vol 261 ◽  
pp. 01013
Author(s):  
Changbao Guo

With the rapid development of modern society, the measurement and control requirements of key variables of air conditioning test technology are also increasing. When the parameters of HVAC system are measured and controlled, there are a large number of sensors and instruments used. When sensor failure or measurement error distortion occurs, the air conditioning system cannot operate normally and automatically. At the same time, some variables in the test parameters cannot be directly collected by the sensor. In order to solve these problems, researchers have focused on soft measurement technology in recent years, which provides a good breakthrough for the measurement and control of air conditioning system test parameters. This paper expounds the application of soft measurement technology in HVAC system.


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