scholarly journals Challenge of Using Groundwater for Buildings Air Conditioning in Subtropical Areas

2021 ◽  
Vol 14 (1) ◽  
pp. 364
Author(s):  
Chih-Ping Kuo ◽  
Hung-Jiun Liao
Keyword(s):  
Latent Heat ◽  
Indoor Air ◽  
High Latitude ◽  
Air Conditioning ◽  
Electrical Power ◽  
Water System ◽  
System Optimization ◽  
Total Power ◽  
Humid Air ◽  
Air Conditioning System

Using circulating groundwater to cool air-conditioning is not new in high latitude regions but difficult in subtropical areas. Different from only using fans to remove the heat from indoor air for drier air in the high latitude region, the latent heat inside the humid air in subtropical areas makes the operation more difficult. Latent heat inside the humid air must remove away by air-conditioning including compressor and fan for cooling indoor air, which means more electrical power is required for the operation. To save total electrical power for the air-conditioning system is the main goal of this study. To use the advantage of groundwater with lower temperature to lower down the work of compressor, this research compared two ways, close/open types of water/groundwater circulation, both using groundwater to remove the heat generated by a 15RT (45 kW) air-conditioning. Full-scale tests and simulations were performed in this study to evaluate the efficiency of transferring the heat produced by air-conditioning systems to stably flowing groundwater in a grave stratum under Taipei Basin. With a closed circulating cooling water system, this study found that a 15RT air conditioner could only operate continuously for 4 h before it had to be shut down due to overheating. Additionally, groundwater must carry the heat away within the following 20 h. In changing the closed circulating water system to an open one, a system that uses a circulatory method to extract groundwater upwards and conduct heat exchange with an air conditioning system can enable the continuous operation of such a system with the same heat production condition. Numerical simulations for the heat dissipation behavior of two circulatory systems were performed herein. The results verified the aforementioned phenomena observed from both tests. The result showed both systems can provide air-conditioning working well. The total electrical power for a 15RT air-conditioning in sub-tropical areas can be reduced by 22% using circulating groundwater. Considering the system optimization, the total power consumption can be reduced by about 28%.

scholarly journals A New Design of an Integrated Solar Absorption Cooling System Driven by an Evacuated Tube Collector: A Case Study for Baghdad, Iraq

2020 ◽  
Vol 10 (10) ◽  
pp. 3622 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Thermal Performance ◽  
Air Conditioning ◽  
Cooling System ◽  
Electrical Power ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Solar Absorption ◽  
Air Conditioning System ◽  
Solar Fraction ◽  
Design Variables

The electrical power consumption of refrigeration equipment leads to a significant influence on the supply network, especially on the hottest days during the cooling season (and this is besides the conventional electricity problem in Iraq). The aim of this work is to investigate the energy performance of a solar-driven air-conditioning system utilizing absorption technology under climate in Baghdad, Iraq. The solar fraction and the thermal performance of the solar air-conditioning system were analyzed for various months in the cooling season. It was found that the system operating in August shows the best monthly average solar fraction (of 59.4%) and coefficient of performance (COP) (of 0.52) due to the high solar potential in this month. Moreover, the seasonal integrated collector efficiency was 54%, providing a seasonal solar fraction of 58%, and the COP of the absorption chiller was 0.44, which was in limit, as reported in the literature for similar systems. A detailed parametric analysis was carried out to evaluate the thermal performance of the system and analyses, and the effect of design variables on the solar fraction of the system during the cooling season.

scholarly journals Transient Effects of Different Ventilation Methods on Car Indoor Air Quality

2015 ◽  
Vol 2 (1) ◽  
pp. 70 ◽  
Author(s):  
Feng-Chyi Duh
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Heat Index ◽  
Transient Effects ◽  
Air Conditioning System ◽  
Carbon Dioxide Concentrations ◽  
Volatile Organic

This study investigated transient effects on the air quality of parked cars and moving cars with and without operating air conditioning. Carbon dioxide, carbon monoxide, volatile organic compounds, and formaldehyde concentrations were measured for comparative analysis. The results showed that simply changing the air conditioning system from internal circulation to external circulation to introduce air from outside reduces carbon dioxide concentrations by more than 50%, volatile organic compound concentrations by more than 77%, and the heat index from 0.1℃/min to less than 0.05 ℃/min. In order to conserve energy and improve car indoor air quality, this study can serve as a reference on healthy car environments.

Air Conditioning System Water Quality and Equipment Condition Investigation and Analysis of Energy Saving Measures

2012 ◽  
Vol 516-517 ◽  
pp. 1224-1228
Author(s):  
Na Liang ◽  
Rui Li
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Water System ◽  
Building Energy ◽  
Development Trend ◽  
Air Conditioning System ◽  
Effective Utilization ◽  
Energy Saving Potential ◽  
Central Air Conditioning ◽  
Points Of View

Due to energy reserves reduces gradually and uneven distribution, all countries pay more and more attention to energy saving and improve the effective utilization of energy, China also attaches great important to this. Energy saving of buildings is a necessary development trend. Air conditioning system as a large important part of building energy consumption has a huge energy-saving potential. This article mainly introduced the related strategies of energy saving in central air conditioning water system from the following three points of view: the water treatment, the cooling tower, and the variable frequency pump.

scholarly journals Simplified Thermal Model and Optimal Control for Chilled Water Pipe in Air-Conditioning System

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Zhida Zhao ◽  
Nanyang Yu ◽  
Tao Yu ◽  
Lisha Ye
Keyword(s):  
Control Strategy ◽  
Thermal Model ◽  
Air Conditioning ◽  
Thermal Characteristic ◽  
State Space Model ◽  
Water System ◽  
Water Pipe ◽  
Preview Control ◽  
Air Conditioning System ◽  
Chilled Water

As an important subsystem in air-conditioning system, water system connects the chiller and terminal equipment. Therefore, it is necessary to develop an accurate thermal model for chilled water pipe to create the suitable indoor temperature and humidity environment. In this paper, the thermal model of the pipe was considered by utilizing the simplified thermal time-delay state-space model with the mass, energy balance, and heat consumption equations. Based on this improved model, the preview control as control strategy for water pipe temperature was proposed, and its robustness and stability were discussed. Subsequently, the performances of this model and control strategy were tested in a fan-coil system simulating with MATLAB and TRNSYS (Transient System Simulation Program). Explicitly, the results show that this model accurately predicts the thermal characteristic, and the average mean squared errors for water temperature were 11.14% and 12.82%, respectively. Meanwhile, the tracking effect of valve controller was better than the control strategy with no preview control.

Influence of Façade Area on Thermal Performance of Building for Cooling Purposes

2018 ◽  
Author(s):  
Hamad H. Almutairi ◽  
Abdulrahman Almutairi ◽  
Jaber H. Almutairi
Keyword(s):  
Air Conditioning ◽  
Power Plants ◽  
Electrical Power ◽  
Electrical Energy ◽  
Building Design ◽  
Renewable Energy Resources ◽  
Air Conditioning System ◽  
Air Conditioners ◽  
Simulation Engine ◽  
Hot Climate

Buildings account for significant energy consumption worldwide particularly in regions where energy patterns influenced primarily by weather. Air conditioning system became an essential evaluation factor during building design and construction. The level of curiosity about air conditioning system efficiency in terms of energy usage is increasing quickly. In Kuwait; which is a hot climate country; air conditioners account for 70% of total electrical power. Electricity in Kuwait is produced entirely by the non-renewable energy resources. This work aims to assess the potential electrical savings that could be acquired by reducing building’s façade area towards East-West directional orientation in Kuwait. For this purpose, a detached building model with uniform geometry; was simulated by Energy Plus Thermal Simulation Engine through its interface with DesignBuilder software. Two cases were developed for the analysis; both have the same simulation inputs. The only difference was the orientation of the facades. The results show a reduction of about 900 kWh cooling annually if the largest facades were positioned towards north and south. The obtained saving in annual basis is attributed to about 420 kWh electrical power. Equivalent CO2 emissions associated with the saved electrical energy from power plants in Kuwait were estimated. The resulted savings are promising for early decision making for prospective buildings to be built in future.

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