scholarly journals Multi-Model Identification of HVAC System

2021 ◽  
Vol 11 (2) ◽  
pp. 668
Author(s):  
Yousef Alipouri ◽  
Lexuan Zhong
Keyword(s):  
Nonlinear System ◽  
Air Conditioning ◽  
Ventilation System ◽  
Model Identification ◽  
Hvac System ◽  
Local Models ◽  
Gap Metric ◽  
Unit System ◽  
Operation Conditions ◽  
Model Approach

Heat, ventilation and air conditioning (HVAC) is a crucial system for maintaining acceptable air quality and keeping the building and its occupants healthy. There are some challenges in controlling and identifying this system as it commonly operates in different operation conditions. Furthermore, various types of un-controlled sources disturb the steady operations. In addition, an HVAC system is an inherently nonlinear system and varies with time. As a result, conventional methods are not successful in identifying and controlling this system. This paper proposes a new multi-model approach in which the clustering and regression steps are performed simultaneously to tackle this problem. Cost functions of clustering and regression steps are combined and optimized using an iterative algorithm. After identifying the local models, a gap metric based approach is used to develop a global model of the process. The proposed approach is tested on a simulated ventilation unit system and real-world dataset. The results show the performance of the proposed method of identifying the ventilation system.

scholarly journals Automatic and Noninvasive Indoor Air Quality Control in HVAC Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
M. C. Basile ◽  
V. Bruni ◽  
F. Buccolini ◽  
D. De Canditiis ◽  
S. Tagliaferri ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Ventilation System ◽  
Hvac Systems ◽  
Hvac System ◽  
Noninvasive Method ◽  
Time Table ◽  
Air Quality Control

This paper presents a methodology for assessing and monitoring the cleaning state of a heating, ventilation, and air conditioning (HVAC) system of a building. It consists of a noninvasive method for measuring the amount of dust in the whole ventilation system, that is, the set of filters and air ducts. Specifically, it defines the minimum amount of measurements, their time table, locations, and acquisition conditions. The proposed method promotes early intervention on the system and it guarantees high indoor air quality and proper HVAC working conditions. The effectiveness of the method is proved by some experimental results on different study cases.

scholarly journals The necessity of HVAC system for the registered architectural cultural heritage building

2018 ◽  
Vol 32 ◽  
pp. 01008 ◽  
Author(s):  
Cătălin George Popovici ◽  
Sebastian Valeriu Hudişteanu ◽  
Nelu-Cristian Cherecheş
Keyword(s):  
Air Conditioning ◽  
Ventilation System ◽  
Winter Season ◽  
Hvac System ◽  
Ansys Fluent ◽  
Air Conditioning System ◽  
National Theatre ◽  
Heritage Building ◽  
External Conditions ◽  
Comfort Parameters

This study is intended to highlight the role of the ventilation and air conditioning system for a theatre. It was chosen as a case study the "Vasile Alecsandri" National Theatre of Jassy. The paper also sought to make a comparison in three distinct scenarios for HVAC Main Hall system - ventilation and air conditioning system of the Main Hall doesn’t work; only the ventilation system of the Main Hall works and ventilation and air conditioning system of the Main Hall works. For analysing the comfort parameters, the ANSYS-Fluent software was used to build a 2D model of the building and simulation of HVAC system functionality during winter season, in all three scenarios. For the studied scenarios, the external conditions of Jassy and the indoor conditions of the theatre, when the entire spectacle hall is occupied were considered. The main aspects evaluated for each case were the air temperature, air velocity and relative humidity. The results are presented comparatively as plots and spectra of the interest parameters.

scholarly journals A Multiple-Model Approach for Synchronous Generator Nonlinear System Identification

2012 ◽  
Vol 63 (4) ◽  
pp. 249-254 ◽  
Author(s):  
Seyed Ahmadi ◽  
Mehdi Karrari
Keyword(s):  
System Identification ◽  
Nonlinear System ◽  
Nonlinear System Identification ◽  
Nonlinear Behavior ◽  
Synchronous Generator ◽  
Operating Conditions ◽  
Model Complexity ◽  
Multiple Model ◽  
Local Models ◽  
Model Approach

A Multiple-Model Approach for Synchronous Generator Nonlinear System Identification In this paper, a multiple model approach is proposed for the identification of synchronous generators. In the literature, the same structure often is used for all local models. Therefore, to obtain a precise model for the operating condition of the synchronous generator with severely nonlinear behavior, many local models are required. The proposed method determines the complexity of local models based on complexity of behavior of the synchronous generator at different operating conditions. There are two choices for increasing model precision at each iteration of the proposed method: (i) increasing the number of local models in one region, or (ii) increasing local model complexity in the same region. The proposed method has been tested on experimental data collected on a 3 kVA micro-machine. In the study, the field voltage is considered as the input and the active output power and the terminal voltage are considered as the outputs of the synchronous generator. The proposed method provides a more precise model with fewer parameters compared to some well known methods such as LOLIMOT and global polynomial models.

scholarly journals A Multi-Timescale Bilinear Model for Optimization and Control of HVAC Systems with Consistency

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 400 ◽  
Author(s):  
Zelin Nie ◽  
Feng Gao ◽  
Chao-Bo Yan
Keyword(s):  
Optimization Model ◽  
Air Conditioning ◽  
State Of The Art ◽  
Hvac Systems ◽  
Practical Significance ◽  
Hvac System ◽  
Bilinear Model ◽  
Optimization And Control ◽  
And Control ◽  
Slow Timescale

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.

scholarly journals Verification of the effect of sleeping environment and humidification on middle-aged people in whole-house air-conditioning ventilation system housing

2019 ◽  
Vol 111 ◽  
pp. 02044
Author(s):  
Akemi Iwaki ◽  
Takashi Akimoto ◽  
Naho Misumi ◽  
Takuya Furuhashi
Keyword(s):  
Blood Pressure ◽  
Moisture Content ◽  
Air Conditioning ◽  
Sleep Latency ◽  
Ventilation System ◽  
Circulation Type ◽  
Living Environment ◽  
Aged People ◽  
Air Circulation ◽  
Skin Moisture

This study focused on the thermal comfort of air circulation-type whole-house air-conditioning ventilation systems. We studied the influence of 24-h continuous whole-house air-conditioning on the living environment in which the occupant is sleeping. A survey was conducted in the summer of 2016 and winter of 2017 to ascertain the influence on the sleeping environment, skin moisture content, and blood pressure. We then compared the results with those of the sleeping environment of residents in air-conditioned housing surveyed the previous year. The sleeping environment when using a personal humidifier around the occupant’s head was examined during winter when the humidity is low. The results indicated that sleep latency was significantly shortened in the 24-h continuous whole-house air-conditioning ventilation system in both summer and winter because the temperature control of the bedroom before going to bed affects the sleep latency. Subjectively, no participants felt dryer than the values measured in the bedroom environment. The results implied that the comfort of the entire building was improved with continuous air-conditioned housing.

Data-Driven Fault Diagnosis for Nuclear Power Plant: The Implicit Model Approach

2018 ◽  
Author(s):  
Zhaoxu Chen ◽  
Xianling Li ◽  
Zhiwu Ke ◽  
Mo Tao ◽  
Yi Feng
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Fault Detection ◽  
Nuclear Power ◽  
Model Identification ◽  
Industrial Process ◽  
Data Driven ◽  
Implicit Model ◽  
Complicated Model ◽  
Model Approach

This paper proposes a data-driven fault detection approach for nuclear power plant. The approach starts from input and output (I/O) data obtained from operating data of industrial process. Due to the model is not explicitly appeared, the proposed approach is named as implicit model approach (IMA). Residual generator is obtained directly from I/O data rather than from the mechanism, based which the algorithm of IMA-based fault detection is proposed. The main advantage of IMA-based fault detection is that it can circumvent complicated model identification. The approach generates parameterized matrices of residual signal inspired by subspace relevant technology without any prior knowledge about mechanisms of the plant. Fault information has been injected to a simulating platform of a compact reactor in the simulation part, by which we verify the effectiveness of IMA-based fault detection.

scholarly journals Study on IBS Cooling Panel Wall System with Difference Types of Cooling Mediums

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Eny Nor Syahira Mohamad Hashim ◽  
◽  
Norhafizah Salleh ◽  
Noor Azlina Abdul Hamid ◽  
◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Conditioning ◽  
Ventilation System ◽  
Target Strength ◽  
Outdoor Temperature ◽  
Design Concepts ◽  
Building Ventilation ◽  
American Society ◽  
Wall System ◽  
Indoor And Outdoor

This paper proposes a cooling house system that can promote thermal comfort in buildings without air-conditioning. The cooling panel wall forms a part of an Integrated Building System (IBS), and is essentially made of tubes filled with either water or glycerin as the coolant. Target strength for the panel wall was designed based on the Malaysian Standard (MS) while the building ventilation system followed the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) standard. The results are reported based on indoor and outdoor temperature difference together with relative humidity to identify the best performing house model and also coolant. The outcome of this research is expected to add value to design concepts with a better promotion of air flow and circulation in the building, without over-usage of natural resources and higher building cost to achieve the same objective.

Sign in / Sign up

Export Citation Format

Share Document