Exergy Analysis of Energy Consumption for Central Air Conditioning System

2014 ◽  
Vol 628 ◽  
pp. 332-337
Author(s):  
Xiao Xia Xia ◽  
Nai Jun Zhou ◽  
Zhi Qi Wang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Dew Point ◽  
Exergy Loss ◽  
Air Conditioning System ◽  
Air Cooler ◽  
Central Air Conditioning ◽  
Air Conditioning Systems

The energy consumption of several central air conditioning systems in summer was researched by the method of exergy analysis. Combined with actual example,the exergy loss of all the equipments and the exergy efficiency of three systems were calculated. The results show that the exergy efficiency of three systems is very low. Relatively speaking, the exergy efficiency of primary return air conditioning system with supplying air in dew point is highest. The equipment of highest exergy loss is air-conditioned room, while the exergy loss of surface air cooler is smallest. Based on this, several improvement measures were proposed to reduce exergy loss and improve exergy efficiency.

Analysis of Energy-Saving Measures on the Operation and Management of Central Air Conditioning System

2013 ◽  
Vol 671-674 ◽  
pp. 2511-2514
Author(s):  
Su Di Gao ◽  
Zheng Wei Pan
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
New Energy ◽  
Central Air Conditioning ◽  
Enhance Efficiency ◽  
Air Conditioning Systems ◽  
Operation And Management

Central air-conditioning systems consume a lot of energy. Determining how to economize energy and enhance efficiency becomes urgently. In this article, the energy-saving measures of the central air-conditioning system are proposed from some aspects which include reasonable design, the momentum energy consumption, the hidden energy consumption, the new energy-saving technologies, etc.

Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Air Supply ◽  
Air Conditioning Systems ◽  
Air Diffusion

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.

Overall Optimization and Exergy Analysis of an Air Conditioning System Using a Series-Series Counterflow Arrangement of Water Chillers

2019 ◽  
Vol 27 (04) ◽  
pp. 1950034 ◽  
Author(s):  
Nguyen Minh Phu
Keyword(s):  
Air Conditioning ◽  
Exergy Analysis ◽  
Cooling Tower ◽  
Exergy Efficiency ◽  
Air Conditioning System ◽  
In Series ◽  
Main Components ◽  
Compressor Power ◽  
Cooling Coil ◽  
Optimal Set

When water chillers are arranged in series-series counterflow (SSCF), the compressor lift of each chiller is decreased in comparison with that of water chillers in parallel. This means that the compressor power of SSCF chillers is lower than that of parallel chillers. In this paper, models of the main components in an air conditioning system were developed and verified to predict the behaviors of the whole system with respect to SSCF chillers. The results showed that performance was maximized with three SSCF chillers when the system was operated with normal set points. The performance was further improved to 26% and decreased with the number of SSCF chillers when the system was operated with optimal set points. The SSCF chiller system also demonstrated higher exergy efficiency regardless of the number of SSCF chillers. The irreversibility of components in SSCF chillers was rather low. However, the irreversibility of the cooling tower and cooling coil was slightly higher and lower, respectively, than those in the parallel chiller system.

scholarly journals Energy Performance Comparison between Two Liquid Desiccant and Evaporative Cooling-Assisted Air Conditioning Systems

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 522
Author(s):  
Su Liu ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Evaporative Cooling ◽  
Dew Point ◽  
Outdoor Air ◽  
Liquid Desiccant ◽  
Energy Saving Potential ◽  
Evaporative Cooler ◽  
Air Conditioning Systems ◽  
Direct Evaporative Cooler

This study investigated the annual energy saving potential and system performance of two different evaporative cooling-based liquid desiccant and evaporative cooling-assisted air conditioning systems. One system used an indirect and direct evaporative cooler with a two-stage package to match the target supply air point. The other was equipped with a single-stage, packaged dew-point evaporative cooler that used a portion of the process air, which had been dehumidified in advance. Systems installed with the two evaporative coolers were compared to determine which one was more energy efficient and which one could provide better thermal comfort for building occupants in a given climate zone, using detailed simulation data. The detailed energy consumption data of these two systems were estimated using an engineering equation solver with each component model. The results showed that the liquid desiccant and dew-point evaporative-cooler-assisted 100% outdoor air system (LDEOAS) resulted in approximately 34% more annual primary energy consumption than that of the liquid desiccant and the indirect and direct evaporative-cooler-assisted 100% outdoor air system (LDIDECOAS). However, the LDEOAS could provide drier and cooler supply air, compared with the LDIDECOAS. In conclusion, LDIDECOAS has a higher energy saving potential than LDEOAS, with an acceptable level of thermal comfort.

The Energy Efficiency Reconstruction and Energy Consumption Assessments about a Library in Guangzhou

2011 ◽  
Vol 374-377 ◽  
pp. 672-676
Author(s):  
Liu Zhi Chen ◽  
Xiao Ning Xu ◽  
Han Wei Liu
Keyword(s):  
Energy Efficiency ◽  
Control System ◽  
Energy Consumption ◽  
Air Conditioning ◽  
Network Control ◽  
Operational Control ◽  
Network Control System ◽  
Air Conditioning System ◽  
Operational Management ◽  
Central Air Conditioning

How to reduce the energy consumption of the central air-conditioning is important for the building energy efficiency. The energy efficiency reconstruction of the central air-conditioning system on one library in Guangzhou is completed with the network control system self-developed. The operational control and operational management is integrated in the network control system. The energy consumption before and after reconstruction about the air-conditioning system of the library is detected and analyzed in the paper. The result shows the mode that operational control and operational management integrated has better energy efficiency.

The Energy Consumption Investigation of the Hotel Central Air-Conditioning System and the Research of Energy Saving Measures

2013 ◽  
Vol 712-715 ◽  
pp. 1614-1618
Author(s):  
Jia Jia Ni ◽  
Li Tao ◽  
Yi Jun Wang ◽  
Jin Lei Wu
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Waste Heat ◽  
Frequency Control ◽  
Building Envelope ◽  
Air Conditioning System ◽  
Central Air Conditioning ◽  
Energy Saving Technology ◽  
System Energy

Through to investigation on present situation of the Changzhou Changrui Hotel air conditioning system energy consumption, by analysis the energy consumption, the power consumption of hotel central air-conditioning system charge 58% of the total electric, accounted for a large proportion. So we should take the necessary measures to reduce the expenses of air conditioning system energy consumption. According to the analysis of data on the survey, we put forward some particular energy-saving measures of central air-conditioning system of the hotel, including strengthening the building envelope insulation, energy saving technology of doors and windows, measures of roof energy saving, setting reasonable indoor temperature, adopting frequency control air-conditioning, reuse waste heat of the central air-conditioning, using the condensation water of central air conditioning to make-up water and reducing temperature of cooling tower , and drying the fresh air independently.

Comparison study of air mixing modes in liquid desiccant based all-air air conditioning systems

2011 ◽  
Vol 33 (4) ◽  
pp. 423-435 ◽  
Author(s):  
Fu Xiao ◽  
XiaoFeng Niu
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Liquid Desiccant ◽  
Total Energy Consumption ◽  
Air Conditioning System ◽  
Operation Conditions ◽  
Air System ◽  
Air Mixing ◽  
Air Conditioning Systems

Liquid desiccant is an energy-saving, environmentally friendly and healthy means of air dehumidification. A liquid desiccant-based all-air air conditioning system is studied by simulation. Two different modes of air mixing between the return air and the fresh air are compared, that is mixing before and mixing after the liquid desiccant dehumidifier, respectively. System performance and total energy consumption of the two modes under different operation conditions are obtained. The results show that mixing air after dehumidification consumes less energy than mixing air before dehumidification. Coefficient of performance (COP) of the all-air system with air mixing after dehumidification is higher. The differences of COP and energy consumption between the two air mixing modes increase when the outdoor air temperature and relative humidity increase. Practical application: Liquid desiccant based all-air system is quite suitable for museums, libraries and computer centres where water is not allowed to enter the space for property safety and strict thermal-hygrometric control is necessary. The results of this paper provide guidelines on the selection of air mixing modes in liquid desiccant-based all-air systems, considering energy consumption and system COP.

Energy Conservation Analysis for Air Conditioning System in Rail Transit Stations

2014 ◽  
Vol 494-495 ◽  
pp. 1674-1677
Author(s):  
Bing Xu ◽  
Fang Hong Yuan ◽  
Bao Guo Zheng ◽  
Zhong Jin Shi ◽  
Yi Huan Hu
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Saving ◽  
Control Strategy ◽  
Air Conditioning ◽  
Rail Transit ◽  
Air Conditioning System ◽  
Conservation Analysis ◽  
Air Conditioning Systems ◽  
Reducing Energy

This article discusses energy conservation for air conditioning systems in rail transit stations. At first, the paper analyzes the energy consumption condition in the air conditioning systems in rail transit stations. Then, it discusses application of appropriate control strategy for reducing energy consumption. In the end, the paper calculates effiency and amount of the energy saving based on the control strategy.

Exergy Analysis and Optimization of a Building Air Conditioning System in Tropical Climate

2014 ◽  
Author(s):  
Ricardo Salazar ◽  
Enrico Sciubba ◽  
Claudia Toro
Keyword(s):  
Renewable Energy ◽  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Use ◽  
Exergy Analysis ◽  
Electric Energy ◽  
Point Of View ◽  
Primary Sources ◽  
Renewable Energy Consumption ◽  
Air Conditioning System

The space conditioning sector is one of the highest exergy consumers and least efficient from the point of view of primary-to-end-use matching. Exergy analysis can be considered as a reliable tool for analyzing and optimizing energy consumption related to building conditioning systems. The present study presents a comparative exergy analysis of the air conditioning system of the TOTAL S.A. offices located in Caracas, Venezuela to finally achieve a reduction of the global electric energy use of the considered building. Starting from the provided thermal cooling load, different possible cooling chains (primary-to-final energy conversion chain) are considered in order to locate the thermodynamically more efficient one from an exergetic point of view. The internal air handler unit, which provides for the cooled and dehumidified air to the building, is fed by the energy obtained from different possible converters of renewable energy primary sources. Specifically, solar and hybrid photovoltaic-thermal (PV/T) panels coupled with an absorption refrigeration machine and with an ejector refrigeration cycle are analyzed. The study that has been carried on leads to identify the most convenient matching between final use and primary sources allowing to substantially reduce the global non-renewable energy consumption of the considered building.

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