Fault Prediction in Air-Conditioning Refrigeration System by Wavelet Transform

A good deal of electricity consumption can be attributed to air-conditioning refrigeration systems. The percentage can be significantly higher if a cooling system is operating at low performance levels due to the presence of faults. The wavelet transform moves data from a time domain to a frequency domain with the wavelet as the basic function giving the localized features of the original signal in the fault detection. It is well known for its capability of treating the transient or time-related varying signals. The fault of heat load increase of the air-conditioning room can be predicted by wavelet transform through the test. Fault prediction in air-conditioning refrigeration system by wavelet transform can avoid defects of the conventional methods.

Download Full-text

System for studies of control strategies applied in the refrigerated chambers

Engenharia Agrícola ◽

10.1590/s0100-69162011000500004 ◽

2011 ◽

Vol 31 (5) ◽

pp. 868-878

Author(s):

Alexandre Tizzei ◽

Carlos R. Meneghetti ◽

Nelson L. Cappelli ◽

Claudio K. Umezu

Keyword(s):

Power Consumption ◽

Fuzzy Controller ◽

Cooling System ◽

Control Strategies ◽

Heat Engine ◽

Electricity Consumption ◽

Stored Products ◽

Refrigeration System ◽

Storage Chamber ◽

Scientific Experiments

The process of cold storage chambers contributes largely to the quality and longevity of stored products. In recent years, it has been intensified the study of control strategies in order to decrease the temperature change inside the storage chamber and to reduce the electric power consumption. This study has developed a system for data acquisition and process control, in LabVIEW language, to be applied in the cooling system of a refrigerating chamber of 30m³. The use of instrumentation and the application developed fostered the development of scientific experiments, which aimed to study the dynamic behavior of the refrigeration system, compare the performance of control strategies and the heat engine, even due to the controlled temperature, or to the electricity consumption. This system tested the strategies for on-off control, PID and fuzzy. Regarding power consumption, the fuzzy controller showed the best result, saving 10% when compared with other tested strategies.

Download Full-text

Solar hybrid air conditioning system to use in Iraq to save energy

E3S Web of Conferences ◽

10.1051/e3sconf/201912401024 ◽

2019 ◽

Vol 124 ◽

pp. 01024

Author(s):

Y. V. Vankov ◽

A. K. Al–Okbi ◽

M. H. Hasanen

Keyword(s):

Air Conditioning ◽

Power Plants ◽

Cooling System ◽

Renewable Energy Sources ◽

Electricity Consumption ◽

Air Conditioners ◽

Reduce Electricity Consumption ◽

Central Air Conditioning ◽

Save Energy ◽

Air Conditioning Systems

The energy saving issues are becoming necessary worldwide, as excessive consumption of energy leads to the consumption of a larger amount of fuel, increases environmental pollution and negatively affects the ozone layer. In Iraq, in particular, the demand for central air conditioning systems and home air conditioners with high electrical capacity has become increasingly clear in the recent years. Air conditioning systems within residential and public buildings, as well as government facilities became a necessity for good internal comfort, which was driven by desertification, high temperature, air pollution and increased population, resulting in increased consumption of electric power and pressing of power plants. Aiming at usage of renewable energy sources, the proposed system uses solar collectors as auxiliary solar thermal compressors and integrate them with air conditioning systems. The proposed solution will increase the cooling system efficiency, reduce electricity consumption and pollution.

Download Full-text

Performance assessment of a solar assisted desiccant cooling system

Thermal Science ◽

10.2298/tsci120526067g ◽

2014 ◽

Vol 18 (2) ◽

pp. 563-576 ◽

Cited By ~ 14

Author(s):

Antonio Gagliano ◽

Francesco Patania ◽

Francesco Nocera ◽

Aldo Galesi

Keyword(s):

Air Conditioning ◽

Cooling System ◽

Electricity Consumption ◽

Primary Energy ◽

Solar Irradiation ◽

Cooling Load ◽

Simulation Data ◽

Direct Flow ◽

And Performance ◽

Solid System

The use of solar energy to drive cooling applications, such as air conditioning is attractive since the cooling load has a high coincidence with the availability of solar irradiation. Combination of solar thermal and cooling has a high potential to reduce the electricity consumption of conventional air conditioning. This work delivers a description of solar desiccant solid system (DECs) and presents results of tests and performance analysis. The overall cooling efficiency is evaluated using simulation data typical of Mediterranean Region. In this context the autonomous operations both of a solar desiccant system (DEC) and an absorption refrigerant (AR) chillers powered by direct-flow vacuum-tube collectors are investigated. It is found out that the DEC system can achieve a primary energy saving (PES) of around 40%, compared to an AR and of around 150% compared to a conventional vapour compressor refrigerator (VCR).

Download Full-text

Exergy analysis of large temperature difference series air conditioners in subway stations

E3S Web of Conferences ◽

10.1051/e3sconf/202016504067 ◽

2020 ◽

Vol 165 ◽

pp. 04067

Author(s):

Kong Xiang jian ◽

Bi Hai quan ◽

He Lei

Keyword(s):

Temperature Difference ◽

Air Conditioning ◽

Cooling System ◽

Water System ◽

Exergy Efficiency ◽

Subway Station ◽

Large Temperature ◽

Refrigeration System ◽

Large Temperature Difference ◽

Difference Series

In view of the large difference in the heat and humidity ratio of each air-conditioning zone in the subway, the unified cooling and dehumidification method is adopted, which changes the traditional connection mode of air-conditioning terminal in parallel. A cooling system of air-conditioning terminal surface cooler in series, i.e. large temperature difference series cooling system, is applied to the subway station. The large temperature difference series cooling system is divided into three subsystems: cooling water system, chilled water system and end refrigeration system. The second law of thermodynamics, namely the law of exergy equilibrium and thermoeconomics, is used to analyze the feasibility and economy of the large temperature difference series system and its subsystems. After comparing energy consumption and economy with the conventional air conditioning system, it was found that the exergy efficiency of the chilled water system using the large temperature difference series cooling system was reduced. However, the exergy efficiency of the end refrigeration system in the subway equipment area has been significantly improved, saving electricity costs, and the investment can be recovered in 3.7 years, and the exergy cost has dropped significantly. The use of a large temperature difference series cooling system in a subway station can achieve the effect of energy saving and cost reduction.

Download Full-text

Feasibility of Reducing Electricity Consumption of Air Conditioning Equipment by Condenser Direct Evaporative Cooling Technology. Example of Case Study in Dubai

Atmosphere ◽

10.3390/atmos12091205 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1205

Author(s):

Anatolijs Borodinecs ◽

Kristina Lebedeva ◽

Aleksejs Prozuments ◽

Arturs Brahmanis ◽

Aldis Grekis ◽

...

Keyword(s):

Air Conditioning ◽

Cooling System ◽

Evaporative Cooling ◽

Electricity Consumption ◽

Air Cooling ◽

Additional Energy ◽

Direct Evaporative Cooling ◽

Evaporative Cooling System ◽

Cooling Technology

The use of air conditioning technology is accompanied by an increase in electricity consumption, which is linked to an intensification of fossil fuel extraction. This in turn calls for developing cooling solutions of higher energy efficiency. The aim of this study is to examine energy consumption reduction of direct evaporative cooling technology for generating cool air in hot-dry climate regions. At the initial stage, already-installed air cooling equipment with a direct evaporative cooling system was studied for the creation of two regression models of electricity consumption representing the “on” and “off” sequences. Water consumption for system operation was taken into consideration. In the following stage, inlet water temperature dependence for pre-cooling purposes for the direct evaporative cooling system was studied. A mathematical model was developed and the subsequent calculations suggested that there is no need to pre-cool water before it enters the system and therefore consume additional energy. Practical application of this study is evaluated based on the case study in Dubai. The results of this study present significant energy saving potential for system operations of the direct evaporative cooling system of approximately 122 MWh per year. The return on investment for the equipment with direct evaporative cooling in case of an office building in Dubai featuring a hot desert climate is around 4.2 years. The purpose of this study is to examine the potential advantage of air cooling equipment with direct evaporative cooling technology compared to cooling equipment without this technology. The results provide the expediency of conducting further research in this area, in particular with regards to analyzing various materials for the adiabatic precooling pads, as well as the possibility of using a newly developed metal precooling pad.

Download Full-text

Optimal Design of Integrated Chiller Capacity with Ice Thermal Storage for Commercial Buildings through Cooling System Cascade Analysis

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b8301.1210220 ◽

2020 ◽

Vol 10 (2) ◽

pp. 165-175

Author(s):

Muhammad Ikhwan Zamhuri ◽

Haslenda Hashim ◽

Ho Wai Shin

Keyword(s):

Air Conditioning ◽

Cooling System ◽

Storage System ◽

Electricity Consumption ◽

Thermal Storage ◽

Commercial Buildings ◽

Optimal Size ◽

Cooling Load ◽

Air Conditioning System ◽

Cascade Analysis

Chilled water air conditioning system is used to supply cooling systems in large capacity for industrial processes and commercial buildings. Air conditioners contribute more than 60 percent of electricity consumption in buildings. District Cooling System (DCS) technology comprises a central chiller plant which provides advantage compared to local air conditioning system. It has higher efficiency, uses less power in system operation, allows more usable space in buildings, and can be operated with minimum manpower while handling same amount of cooling load. The integration of a chiller with ice thermal storage (ITS) offers more operational flexibility while reducing space cooling expenses. This paper presents a systematic framework for design and operation of District Cooling Plant (DCP) comprising an integrated chiller and ice thermal storage system. The Cooling System Cascade Analysis (COSCA) based on pinch analysis is constructed to determine the chiller optimal size and ice thermal storage capacity. The District Cooling System configuration for this study comprises a cooling tower, chiller (centrifugal, variable centrifugal, glycol) and ice thermal storage system. The application of this technique to fulfil 66,284 refrigerant tonne hour (RTH) cooling load demand from commercial buildings reveals the optimal capacity of the chiller is 3068.91 refrigerant tonne (RT), ice tank rating at 989 refrigerant tonne (RT) and ice tank capacity is 9892.75 refrigerant tonne hour (RTH).

Download Full-text

Effect of Condenser Length on Performance of Water Cooling Refrigeration System Cum Air Coolera

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.f4182.049620 ◽

2020 ◽

Vol 9 (4) ◽

pp. 1463-1467

Keyword(s):

Air Conditioning ◽

Cooling System ◽

Electrical Energy ◽

Air Cooling ◽

Water Cooling ◽

Refrigeration System ◽

Energy And Environment ◽

Humid Condition ◽

Chilled Water ◽

Air Cooling System

Now a days Air conditioning system has become a need for everyone to feel comfort in hot and humid condition and everyone feels comfortable to drink chilled water for quenching the thirst of the people. According to American Society of Heating, Refrigerating and Air conditioning Engineers in short ASHRAE Human comfort is defined as the condition of mind which expresses satisfaction with surrounding air. In this project, we developed the water cooling refrigerator and air cooling system by combining both the systems through which water is chilled by an eco-friendly refrigerant R-134a and then the air is cooled by this chilled water. Performance analysis of the water cooling refrigeration system was done and analyzed with varying condenser length. By combining these both systems we can reduce the compressor work, cost, save the electrical energy and environment too.

Download Full-text

ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

Computational nanotechnology ◽

10.33693/2313-223x-2019-6-3-86-91 ◽

2019 ◽

Vol 6 (3) ◽

pp. 80-85

Author(s):

Denis Igorevich Smagin ◽

Konstantin Igorevich Starostin ◽

Roman Sergeevich Savelyev ◽

Anatoly Anatolyevich Satin ◽

Anastasiya Romanovna Neveshkina ◽

...

Keyword(s):

Conceptual Design ◽

Air Conditioning ◽

Research University ◽

Cooling System ◽

Fuel Efficiency ◽

Air Cooling ◽

Moscow Aviation Institute ◽

Air Conditioning System ◽

Low Efficiency ◽

Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

Download Full-text