Optimizing an Automotive HVAC System for Enhancement of Acoustic Comfort

2019 ◽

Vol 16 (2) ◽

pp. 6634-6648

Author(s):

A. Z. A. Mazlan ◽

M. H. A. Satar ◽

M. H. Hamdan ◽

M. S. Md. Isa ◽

S. Man ◽

...

Keyword(s):

Vibration Characteristics ◽

Operating Conditions ◽

Hvac System ◽

Frequency Range ◽

Noise And Vibration ◽

Power Steering ◽

Pump Compressor

The automotive heating and ventilating air condition (HVAC) system, when vibrating, can generate various types of noises such as humming, hissing, clicking and air-rushes. These noises can be characterised to determine their root causes. In this study, the humming-type noise is taken into consideration whereby the noise and vibration characteristics are measured from various HVAC components such as power steering pump, compressor and air conditional pipe. Four types of measurement sensors were used in this study - tachometer for rpm tracking; accelerometer for the vibration microphone for the noise; and sound camera for the visualization measurement. Two types of operating conditions were taken into consideration - they were “idle” (850 rpm) and “running” (850-1400 rpm) conditions. A constant blower speed was applied for both conditions. The result shows that the humming noises can be determined at the frequency range of 300-350 Hz and 150-250 Hz for both idle and running conditions, respectively. The vibration of the power steering pump shows the worst acceleration of 1.8 m/s2 at the frequency range of 150-250 Hz, compared to the compressor and air conditional pipe. This result was validated with the 3D colour order and sound camera analyses, in which the humming noise colour mapping shows dominance in this frequency range.

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Application of Green Idea in Energy-Saving Design of Building Hvac System

Journal of Architectural Research and Development ◽

10.26689/jard2017.v1i1.48 ◽

2017 ◽

Vol 1 (1) ◽

pp. 11-14

Author(s):

Fu Xiaogeng

Keyword(s):

Energy Saving ◽

Hvac System

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Numerical Evaluation of a HVAC System Based on a High-Performance Heat Transfer Fluid

Energies ◽

10.3390/en14113298 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3298

Author(s):

Gianpiero Colangelo ◽

Brenda Raho ◽

Marco Milanese ◽

Arturo de Risi

Keyword(s):

Heat Transfer ◽

High Performance ◽

Cooling System ◽

Electrical Energy ◽

Simulation Software ◽

Heat Transfer Fluid ◽

Hvac System ◽

Dynamic Simulations ◽

Heating And Cooling ◽

The University

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

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Prediction of Key Crop Growth Parameters in a Commercial Greenhouse Using CFD Simulation and Experimental Verification in a Pilot Study

Agriculture ◽

10.3390/agriculture11070658 ◽

2021 ◽

Vol 11 (7) ◽

pp. 658

Author(s):

Subin Mattara Chalill ◽

Snehaunshu Chowdhury ◽

Ramanujam Karthikeyan

Keyword(s):

Pilot Study ◽

Cfd Simulation ◽

Growth Parameters ◽

Environmental Parameters ◽

Pilot Scale ◽

Crop Growth ◽

Hvac System ◽

Implementation Phase ◽

Design And Implementation ◽

Successful Design

Controlled crop growth parameters, such as average air velocity, air temperature, and relative humidity (RH), inside the greenhouse are necessary prerequisites for commercial greenhouse operation. Frequent overshoots of such parameters are noticed in the Middle East. Traditional heating ventilation and air-conditioning (HVAC) systems in such greenhouses use axial fans and evaporative cooling pads to control the temperature. Such systems fail to respond to the extreme heat load variations during the day. In this study, we present the design and implementation of a single span, commercial greenhouse using box type evaporative coolers (BTEC) as the backbone of the HVAC system. The HVAC system is run by a fully-automated real time feedback-based climate management system (CMS). A full-scale, steady state computational fluid dynamics (CFD) simulation of the greenhouse is carried out assuming peak summer outdoor conditions. A pilot study is conducted to experimentally monitor the environmental parameters in the greenhouse over a 20-h period. The recorded data confirm that the crop growth parameters lie within their required ranges, indicating a successful design and implementation phase of the commercial greenhouse on a pilot scale.

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A constrained distributed time-series neural network MPC approach for HVAC system energy saving in a medium-large building

Journal of Building Performance Simulation ◽

10.1080/19401493.2021.1951841 ◽

2021 ◽

Vol 14 (4) ◽

pp. 383-400

Author(s):

Omid Asvadi-Kermani ◽

Hamidreza Momeni

Keyword(s):

Neural Network ◽

Time Series ◽

Energy Saving ◽

Hvac System ◽

System Energy ◽

Large Building

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

Energies ◽

10.3390/en14020400 ◽

2021 ◽

Vol 14 (2) ◽

pp. 400 ◽

Cited By ~ 1

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.

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