Prediction method of energy efficiency ratio of central air-conditioning operation based on extreme learning machine

2020 ◽  
Author(s):  
Dongming Sun ◽  
Chaoyang Fei
Keyword(s):  
Energy Efficiency ◽  
Extreme Learning Machine ◽  
Air Conditioning ◽  
Prediction Method ◽  
Efficiency Ratio ◽  
Central Air Conditioning ◽  
Learning Machine

scholarly journals Occupancy Prediction Using Differential Evolution Online Sequential Extreme Learning Machine Model

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 4033
Author(s):  
Jonas Bielskus ◽  
Violeta Motuzienė ◽  
Tatjana Vilutienė ◽  
Audrius Indriulionis
Keyword(s):  
Energy Efficiency ◽  
Differential Evolution ◽  
Extreme Learning Machine ◽  
Open Space ◽  
Prediction Models ◽  
Co2 Concentration ◽  
Full Potential ◽  
Machine Model ◽  
Learning Machine ◽  
Occupancy Prediction

Despite increasing energy efficiency requirements, the full potential of energy efficiency is still unlocked; many buildings in the EU tend to consume more energy than predicted. Gathering data and developing models to predict occupants’ behaviour is seen as the next frontier in sustainable design. Measurements in the analysed open-space office showed accordingly 3.5 and 2.7 times lower occupancy compared to the ones given by DesignBuilder’s and EN 16798-1. This proves that proposed occupancy patterns are only suitable for typical open-space offices. The results of the previous studies and proposed occupancy prediction models have limited applications and limited accuracies. In this paper, the hybrid differential evolution online sequential extreme learning machine (DE-OSELM) model was applied for building occupants’ presence prediction in open-space office. The model was not previously applied in this area of research. It was found that prediction using experimentally gained indoor and outdoor parameters for the whole analysed period resulted in a correlation coefficient R2 = 0.72. The best correlation was found with indoor CO2 concentration—R2 = 0.71 for the analysed period. It was concluded that a 4 week measurement period was sufficient for the prediction of the building’s occupancy and that DE-OSELM is a fast and reliable model suitable for this purpose.

The Economic Performance of Ground-Source Heat Pumps

2014 ◽  
Vol 919-921 ◽  
pp. 1735-1738 ◽  
Author(s):  
Peng Gong ◽  
Jian Tang
Keyword(s):  
Energy Efficiency ◽  
Total Energy ◽  
Heat Pump ◽  
Air Conditioning ◽  
Ground Source Heat Pump ◽  
Ground Source Heat Pumps ◽  
Heating Systems ◽  
Ground Source ◽  
Groundwater Heat Pump ◽  
Central Air Conditioning

Ground-Source Heat Pump (PSHP) was verified by US Environmental Protection Agency (EPA) as one of the most efficient air conditioning systems on present market. It has a higher efficiency than other heating systems from 50% to 70%, and a higher efficiency than other cooling systems from 30% to 50%. The working principle of PSHP determines its low operating costs. By comparing the total energy efficiency, the existing groundwater heat pump total energy efficiency is the highest, about 115%. The total energy efficiency for soil-source heat pump is up to 100%. But traditional air conditioning is far less than the level. Articles present a research on Ground-Source Heat Pump system and its cost with a scientific and objective principles. Ground-source heat pump is a new central air conditioning system of Low-carbon energy saving. Due to the high technical content, function requirement, and installation difficulty , the average initial investment of ground-source heat pump is much higher than traditional central air conditioning. Taking into account the added costs of heating systems based on traditional central air-conditioning, such as boilers, it will not deviate too much from it.

USING WATER VAPOR AS REFRIGERANT IN MULTISTAGE VARIABLE SPEED TURBO COMPRESSOR TO IMPROVE SEASONAL ENERGY EFFICIENCY RATIO OF AIR CONDITIONING

2011 ◽  
Vol 19 (02) ◽  
pp. 131-140
Author(s):  
QUBO LI ◽  
DEMISS A. AMIBE ◽  
NORBERT MÜLLER
Keyword(s):  
Energy Efficiency ◽  
Water Vapor ◽  
Energy Demand ◽  
Air Conditioning ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Variable Speed ◽  
Efficiency Ratio ◽  
Part Load

An air conditioning system using water as refrigerant (R718) that compresses water vapor with multistage stage variable speed axial compressor with intercooling between stages by water injection is considered. Four stage compression with flash intercooling resulted in 50% improvement of coefficient of performance (COP) at full load compared to conventional refrigerants like R134a. The energy efficiency of an air conditioning unit is specified by seasonal energy efficiency ratio (SEER). SEER is defined as the ratio of cooling output of an air conditioner measured and electrical energy consumption as per AHRI 210/240 during cooling season. The SEER is computed after determining the evaporator cooling capacity and the electrical energy demand of the compressor at each bin temperature using assumed compressor isentropic efficiency, mechanical efficiency and electrical efficiency and multiplying by the weight of each bin temperature to determine the total for the cooling season. As a result of multistage compression, best part load performance of water as a refrigerant and operation of compressor near design point at part load due to variable speed drive, 50%–60% improvement in SEER is obtained compared to the best available in the market using conventional refrigerants such as R134a with single stage compression.

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 Experiment on System Performance Comparing Analysis and Displacement between R1270 and R22

2015 ◽  
Vol 799-800 ◽  
pp. 770-773
Author(s):  
Zhi Jiang Wu
Keyword(s):  
Energy Efficiency ◽  
Heat Exchanger ◽  
Performance Optimization ◽  
System Performance ◽  
Air Conditioning ◽  
Tube Diameter ◽  
Experimental Results ◽  
Efficiency Ratio

The refrigeration circle performance of air conditioning comparing analysis and displacement between R1270 and R22 is studied in this paper. In addition, the system performance optimization of R1270 refrigeration circle is discussed.The experimental results show that the smaller tube diameter of heat exchanger for R1270 system is easy to improve the energy efficiency ratio in the unimproved system.These results are important for theory and reality to research this type of air conditioning.

scholarly journals Comparative Analysis of Power Efficiency and Cooling Capacity Between Central AC and Split AC on Economy Trains

2018 ◽  
Vol 2 (2) ◽  
pp. 110-119
Author(s):  
Mariana Diah Puspitasari
Keyword(s):  
Energy Efficiency ◽  
Comparative Analysis ◽  
Service Quality ◽  
Power Efficiency ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Air Conditioners ◽  
Train Station ◽  
Central Air Conditioning

PT KAI (Persero) has never stopped transforming itself. His transformation was highly considered when PT KAI (Persero) was under the authority of Jonan Ignasius. Edi Sukmoro then continued the transformation. Some improvements in service quality at each train station require appreciation from various aspects. At present, security is improved, tickets are easier to obtain, and travel is more convenient because trains are provided by AC. However, given the costs involved, installation of air conditioners in all business and economy class cars does not apply central air conditioning but divides air conditioning as applied in the home or office. This research is to find out the most efficient air conditioning in consuming energy in trains, therefore, it is conducted. This study also investigates the most effective air conditioning in cooling. The results showed that the energy efficiency of split air coolers was lower than central air coolers. Regarding cooling capacity, central AC is produced by PT INKA which has a higher cooling capacity than split AC.

scholarly journals Prediction method of flow instability based on multi-objective optimized extreme learning machine

2014 ◽  
Vol 63 (20) ◽  
pp. 200505
Author(s):  
Chen Han-Ying ◽  
Gao Pu-Zhen ◽  
Tan Si-Chao ◽  
Fu Xue-Kuan
Keyword(s):  
Extreme Learning Machine ◽  
Flow Instability ◽  
Prediction Method ◽  
Multi Objective ◽  
Learning Machine

scholarly journals Performance of Air Conditioning Unit under Constant Outdoor Wet-Bulb Temperature and Varied Dry-Bulb Temperature

2021 ◽  
Vol 39 (5) ◽  
pp. 1483-1490
Author(s):  
Andriyanto Setyawan ◽  
Susilawati Susilawati ◽  
Tandi Sutandi ◽  
Hafid Najmudin
Keyword(s):  
Energy Efficiency ◽  
Air Temperature ◽  
Air Conditioning ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Outdoor Air ◽  
Efficiency Ratio ◽  
Liquid Line ◽  
Discharge Temperature ◽  
Line Temperature

An experiment has been carried out for examining the performance of an air conditioning unit under constant outdoor wet-bulb temperature and varied dry-bulb temperature. During the experiment, the wet-bulb temperature of the compartment for outdoor unit was maintained at 22℃ and the dry-bulb temperature was varied from 24℃ to 36℃. The increase of outdoor air temperature results in the increase of supply air temperature, discharge temperature, suction temperature, and liquid line temperature. These cause the degradation of the air conditioner performance. An increase of power consumption by 1.4% and decrease of cooling capacity by 0.8% were observed for each 1℃ increase of outdoor air temperature. As a result, the energy efficiency ratio drops by 2% for each 1℃ increase of outdoor air temperature.

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