scholarly journals Systematic Method for the Energy-Saving Potential Calculation of Air-Conditioning Systems via Data Mining. Part I: Methodology

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 81
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  
Keyword(s):  
Data Mining ◽  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Storage System ◽  
Operation Mode ◽  
Systematic Method ◽  
Potential Analysis ◽  
Energy Saving Potential ◽  
Air Conditioning Systems

Air-conditioning systems contribute the most to energy consumption among building equipment. Hence, energy saving for air-conditioning systems would be the essence of reducing building energy consumption. The conventional energy-saving diagnosis method through observation, test, and identification (OTI) has several drawbacks such as time consumption and narrow focus. To overcome these problems, this study proposed a systematic method for energy-saving diagnosis in air-conditioning systems based on data mining. The method mainly includes seven steps: (1) data collection, (2) data preprocessing, (3) recognition of variable-speed equipment, (4) recognition of system operation mode, (5) regression analysis of energy consumption data, (6) constraints analysis of system running, and (7) energy-saving potential analysis. A case study with a complicated air-conditioning system coupled with an ice storage system demonstrated the effectiveness of the proposed method. Compared with the traditional OTI method, the data-mining-based method can provide a more comprehensive analysis of energy-saving potential with less time cost, although it strongly relies on data quality in all steps and lacks flexibility for diagnosing specific equipment for energy-saving potential analysis. The results can deepen the understanding of the operating data characteristics of air-conditioning systems.

scholarly journals Systematic Method for the Energy-Saving Potential Calculation of Air Conditioning Systems via Data Mining. Part II: A Detailed Case Study

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 86
Author(s):  
Rongjiang Ma ◽  
Shen Yang ◽  
Xianlin Wang ◽  
Xi-Cheng Wang ◽  
Ming Shan ◽  
...  
Keyword(s):  
Data Mining ◽  
Energy Saving ◽  
Air Conditioning ◽  
Cost Savings ◽  
Systematic Method ◽  
Efficient Operation ◽  
Energy Saving Potential ◽  
Detailed Case ◽  
Air Conditioning Systems

Increased data monitoring enables the energy-efficient operation of air-conditioning systems via data-mining. The latter is projected to have lesser consumption but more comprehensive diagnosis than traditional methods. Following the companion paper that proposed a systematic method for energy-saving potential calculations via data-mining, this article presents a detailed case study in an ice-storage air-conditioning system by employing the proposed method. Raw data were preprocessed prior to recognizing the constant- and variable-speed devices in the system. Classification and regression tree algorithms were utilized to identify the operating modes of the system. The regression models between the energy-consumption and operating-state parameters of the nine pumps and two chillers were fitted. Furthermore, the constraints pertaining to system operation were summarized. From the results, the particle swarm optimization method was applied to elucidate the benchmark energy cost and the consequent cost savings potential. The cost savings potential for the chiller plant room during the investigation duration of 59 d reached as high as 24.03%. The case study demonstrates the feasibility, effectiveness, and stability of the systematic approach. Further studies can facilitate the development of corresponding control strategies based on the potential analysis results, to investigate better optimization algorithm, and visualize the analysis process.

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.

Analysis for Energy Savings Potential and Economics of Combined Air-Conditioning System with Temperature and Humidity Decoupled Treatment

2011 ◽  
Vol 280 ◽  
pp. 71-75
Author(s):  
Zhong Chao Zhao ◽  
Dong Hui Zhang ◽  
Yu Ping Chen
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Energy Savings ◽  
Operating Cost ◽  
Air Conditioning System ◽  
Operation Mechanism ◽  
Energy Saving Potential ◽  
Temperature And Humidity

In this paper, the operation mechanism of combined air-conditioning system with temperature and humidity decoupled treatment (CACSTHDT) was presented, and the energy saving potential and economics of CACSTHDT were primarily analyzed through compared with a traditional air-conditioning system. The results indicated that CACSTHDT could save up to 28.64% energy consumption in comparison with a traditional air-conditioning system. The operating cost in one summer only was 71.36% of that cost of traditional air-conditioning system.

The Studies on the Energy Consumption Quota of State Organ Office Buildings

2011 ◽  
Vol 243-249 ◽  
pp. 5899-5904 ◽  
Author(s):  
Yu Yun Li ◽  
Kai Guo ◽  
Ran Du ◽  
Hai Cheng Li ◽  
Yun Guo Yang
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Office Buildings ◽  
Government Organization ◽  
Energy Saving Potential ◽  
Current Stage

The paper gives energy consumption indexes of government organization office buildings at the current stage, and then analyses energy-saving potential of office buildings. Further, it discusses building consumption has a correlation between the heating form of air conditioning and personnel density. Finally, the paper presents the energy consumption quota and the formulating method of using energy quota of state organ office buildings at the current stage.

scholarly journals Utilizing the solar thermal ice storage system in improving the energy, exergy, economic and environmental assessment of conventional air conditioning system

2021 ◽  
Author(s):  
Mohamed Elhelw ◽  
Wael M. El-Maghlany ◽  
Mohamed Shawky Ismail ‎
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Storage System ◽  
Water System ◽  
Maximum Energy ◽  
Ice Storage ◽  
Air Conditioning System ◽  
Air System ◽  
Alexandria City ◽  
Air Conditioning Systems

Abstract This paper introduces novel modification for conventional air conditioning systems through utilizing a thermal ice storage system integrated with solar panels. Alexandria and Aswan, cities in Egypt, are chosen to represent two climates for hot-humid and hot-dry climates respectively. The governing equations for both heat and mass transfer are theoretically solved. Exergy analysis is performed for the proposed solar-ice thermal storage system via determining exergy destruction on ice and solar components as well as the total destruction based on transient analysis. This study was carried out on two common types of air conditioning systems, an air handling unit and fan coil unit. Results showed that, solar-ice storage system is more effective approach in hot-humid climate than hot-dry climate and more efficient with all-water air conditioning system than with all-air conditioning system. The maximum energy saving is 205.16 GJ having a percent of 27.5% in August for all water system in case of Alexandria city and 224.67 GJ with a percent of 25.38% in August for all-water system in case of Aswan city. All air system simulation showed maximum energy saving of 175.05 GJ with a percent of 18.13 % in case of August for Alexandria and 175.45 GJ having a percentage of 17.43% in case of Aswan in August. Moreover, the all-water system achieved a reduction in CO2 emissions by 467 tons/year in Aswan city and 390 tons/year in case of Alexandria city. While these reductions decrease to be 435 and 353 tons/year when the all-air system used for the same two cities.

Energy Audits and Energy-Saving Potential Analysis of the Science Building at Xi'an Jiaotong-Liverpool University in Suzhou

2013 ◽  
Vol 291-294 ◽  
pp. 1044-1049 ◽  
Author(s):  
Wen Long Jing ◽  
Mohamed Nayel
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Building Energy ◽  
Building Energy Consumption ◽  
Energy Audit ◽  
Potential Analysis ◽  
Energy Saving Potential ◽  
Science Building ◽  
Energy Audits

A building energy audit was developed through a case study on the science building at Xi'an Jiaotong-Liverpool University (XJTLU). The annual energy consumption of the building was surveyed over a two year period. The building energy consumption characteristics were displayed and the corresponding energy saving potential was analyzed. Additionally, an energy saving methods is proposed based on the characteristics of the target building.

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.

Dividing air handling loads into different grades and handling air with different grade energies

2020 ◽  
pp. 1420326X2096150
Author(s):  
Gonghang Zheng ◽  
Xianting Li
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Air Cooling ◽  
Air Conditioning System ◽  
Energy Saving Potential ◽  
Air Handling Unit ◽  
Chilled Water ◽  
Heating Load ◽  
Heating Loads

In traditional air-conditioning system, low-temperature chilled water is used to cool air. Generally, the temperature difference between air to be operated and the chilled water is high, and majority of air can be operated using water at higher temperatures. Therefore, this paper proposes the concept of grade of load and the method of dividing cooling/heating load into different grades. A traditional air cooling/heating load and energy consumption of fresh air handling unit (FAHU) in Beijing, were compared with cooling/heating loads with different grades and energy consumption of FAHU with different grade energies. The results indicate that cooling and heating loads, handled by the lowest and highest water temperatures of 9.5°C and 37.5°C, account for 27% and 25% of cooling and heating loads in design conditions, respectively. The cumulative cooling/heating load handled by water temperature with highest grade, only accounts for 47%/35% of the total cumulative cooling/heating load. As compared to traditional air handling process, the energy-saving rate of FAHU using different grade energies is 16.4% in summer and 25.6% in winter. This study shows that handling air with different grade energies has significant energy-saving potential for air-conditioning system.

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