Experimental Investigation of a Desiccant Wheel Cycle

2012 ◽  
Author(s):  
Ali Al-Alili ◽  
Yunho Hwang ◽  
Reinhard Radermacher
Keyword(s):  
Air Conditioning ◽  
Removal Rate ◽  
Dew Point ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Air Conditioners ◽  
Considerable Portion ◽  
Temperature Heat ◽  
Air Conditioning Systems ◽  
Desiccant Material

In hot and humid regions, removal of moisture from the air represents a considerable portion of the air conditioning load. Conventionally, air conditioning systems have to lower the air temperature below its dew point to accomplish dehumidification. Desiccant air conditioners offer a solution to meet the humidity and temperature requirements of buildings via decoupling latent and sensible loads. In this work, the performance of a new desiccant material is investigated experimentally. This desiccant material can be regenerated using a low temperature heat source, as low as 45°C. It also has a unique S-shape isotherm. The effects of the process air stream’s temperature and humidity, the regeneration temperature, the ventilation mass flow rate, and the desiccant wheel’s rotational speed on the cycle performance are investigated. ARI-humid conditions are used as a baseline and the moisture mass balance is maintained within 5%. The results are presented in terms of the moisture removal rate and latent coefficient of performance (COPlat). The results show a desiccant wheel’s COPlat higher than unity when it is coupled with an enthalpy wheel.

scholarly journals Absorption and adsorption chillers applied to air conditioning systems

2010 ◽  
Vol 31 (2) ◽  
pp. 77-94 ◽  
Author(s):  
Agnieszka Kuczyńska ◽  
Władysław Szaflik
Keyword(s):  
Heat Source ◽  
Air Conditioning ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Geothermal Heat ◽  
Pump System ◽  
Desorption Process ◽  
Heat Pump System ◽  
Adsorption Chiller ◽  
Air Conditioning Systems

Absorption and adsorption chillers applied to air conditioning systemsThis work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperatureTdes= 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling waterTc= 25 °C and temperature in evaporatorTevap= 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.

scholarly journals Methodology of software development for artificial microclimate control systems

2020 ◽  
pp. 21-31
Author(s):  
Ihor Golinko ◽  
Pavlo Gikalo
Keyword(s):  
Control System ◽  
Software Development ◽  
Control Systems ◽  
Mass Exchange ◽  
Air Conditioning ◽  
Block Diagram ◽  
Dew Point ◽  
Program Logic ◽  
Air Conditioners ◽  
Exchange Processes

The specificity of accelerated software development for microcontrollers is considered. The software development technique for a program-logic controller is presented on the example of an algorithm for controlling the industrial premises microclimate. The method of “dew point” for the control system of industrial air conditioning. The analysis of the functioning of the control system of industrial air conditioning according to the “dew point” method has been carried out and a block diagram of the control system of an artificial microclimate has been proposed. Structurally, the mathematical description of an artificial microclimate system is presented, which takes into account the nonlinearity of mass-exchange processes of air preparation. It can be used by specialists to implement computer-integrated technologies and to analyze and adjust the parameters of the control system of industrial air conditioners.

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.

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.

Numerical Simulation of a Desiccant Bed for Solar Air Conditioning Applications

1991 ◽  
Vol 113 (2) ◽  
pp. 80-88 ◽  
Author(s):  
S. Farooq ◽  
D. M. Ruthven
Keyword(s):  
Numerical Simulation ◽  
Cycle Time ◽  
Air Conditioning ◽  
Removal Rate ◽  
Optimal Choice ◽  
Coefficient Of Performance ◽  
Thermal Coefficient ◽  
Moisture Removal ◽  
Cyclic Operation

The cyclic operation of a desiccant bed used for solar air conditioning applications has been simulated numerically. The results suggest that the optimal choice of desiccant is not seriously limited by the shape of the isotherm since the effect of isotherm shape on the moisture removal rate can be adequately compensated by appropriate adjustment of the cycle time. The conditions required to maximize the moisture removal rate for any given degree of nonlinearity also satisfy the requirements for maximizing the thermal coefficient of performance.

scholarly journals Improving performance of direct expansion air conditioning systems while reducing electricity consumption through using hybrid energy

2021 ◽  
Vol 289 ◽  
pp. 01014
Author(s):  
Ahmed Al–Okbi ◽  
Yuri Vankov ◽  
Hakim Kadhim
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Air Conditioning ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Electricity Production ◽  
Conventional System ◽  
Solar Thermal Energy ◽  
Continuous Power ◽  
Air Conditioning Systems

At the present time, operating hybrid air-conditioning systems that use solar energy to saving electrical energy while improving the performance has become necessary to protect the environment, reduce pollution and emissions caused by using fuels and gases. In Iraq, temperatures reach half the boiling point at summer, therefore the demand for air conditioning systems increases, air conditioning systems consume more than half of average electricity production which affects on reliability and stability of the electrical energy thus leads to a continuous power outage. So, the issue of using renewable energies becomes more attractive. Because of saving energy leads to ensuring the reliability of electricity and reduces the consumption of fuels and gases that pollute on the environment and negatively affect on the ozone layer. In the current research, the atmosphere of Baghdad city was used to collect solar thermal energy and convert it into thermal energy through an evacuated solar collector by water and combine it with a conventional air conditioner in the part that follows the compressor in order to reduce the electrical energy consumption on the compressor and increase coefficient of performance. Several tests were conducted on the proposed system to compare results with the conventional system and evaluate performance. The results showed that the coefficient of performance with the hybrid system became 8.97 more efficient instead of 4.27 compared to the conventional system, and the energy consumption decreased by 52%.

scholarly journals Validation of An Instrument to Know the Use of Smart Devices in Air Conditioners and Their Improvement in Energy Efficiency: Case Study in Ecuador

2021 ◽  
Vol 17 (04) ◽  
pp. 133
Author(s):  
Jorge Israel Anchundia-Santana ◽  
Julieta Evangelina Sánchez-Cano ◽  
Washington Garcia-Quilachamin ◽  
Evelyn Isabel Santana-Mantuano
Keyword(s):  
Energy Efficiency ◽  
Air Conditioning ◽  
Fossil Fuels ◽  
Online Survey ◽  
Smart Devices ◽  
Air Conditioners ◽  
Industrial Sectors ◽  
The Republic ◽  
Air Conditioning Systems

The constant growth of the world’s population has generated various changes in the use of the diversity of the resources provided to us by the planet. Considering that by properly managing energy in air conditioning systems correctly, it collaborates in the fight against climate change, reducing the excessive use of fossil fuels and, therefore, the emission of CO2 and other greenhouse gases, creating an environment of comfort in industrial sectors, businesses, companies, homes, among others. The objective of this research is to validate the instrument considering the information obtained about smart devices applied in air conditioning systems and their improvement in energy efficiency. The methodology applied consisted of a field study conducted through an online survey that was directed at 226 students and professionals from three provinces of the Republic of Ecuador. To validate the data obtained in the instrument, the exploratory factor analysis was performed also of the principal components in the last phase it was obtained in factor transformation matrix (0.986), which demonstrates the validity of the study. To apply the KMO test and Bartlett’s sphericity, the following ranges (≥0.6) y (<0.05) were considered respectively.

Experiences With Thermal Driven, Desiccant Assisted Air Conditioning Systems in Germany

2007 ◽  
Author(s):  
G. Schmitz ◽  
A. Joos ◽  
W. Casas
Keyword(s):  
Air Conditioning ◽  
Power Plants ◽  
Energy Savings ◽  
Measurement Data ◽  
Electricity Consumption ◽  
Heating System ◽  
Primary Energy ◽  
Dew Point ◽  
Water Evaporation ◽  
Air Conditioning Systems

During summer, the use of conventional electrically driven air conditioning systems often results in high electricity consumption. On the other hand, heat demand is very low, therefore heat from Combined Heat and Power plants (CHP) or from solar collectors can not be used. Thermal driven desiccant assisted air conditioning systems offer the possibility to shift energy requirements from electricity to heat. Furthermore, as sorptive pre-drying air doesn’t require cooling under dew point for dehumidifying nor any subsequent heating, cold sources at higher temperatures (e.g. 18°C) can be used for cooling. Within the scope of research projects, different demonstration plants for office buildings and a private bungalow were built, where the operations were evaluated by the Hamburg University of Technology. One plant combines a desiccant wheel with a small (5 kWel) gas driven co-generation plant. Instead of an electric chiller or a water evaporation system (desiccant evaporating cooling), borehole heat exchangers in combination with a radiant floor heating system were used for cooling in summer. In this paper, performance comparisons with conventional systems based on numerical simulations and measurement data are shown, including a cost analysis. It is found that the combination of desiccant wheels and earth energy systems offers considerable energy savings compared to conventional electric systems. The operation of such systems is also cost-effective. It can lead to a reduction of up to 28% of primary energy consumption in a whole year compared to a conventional A/C system.

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

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.

Development of Heating and Cooling Local Air Conditioning System for Houses

2018 ◽  
Vol 931 ◽  
pp. 920-925
Author(s):  
Zohrab Melikyan ◽  
Naira Egnatosyan ◽  
Siranush Egnatosyan
Keyword(s):  
Air Conditioning ◽  
Point Of View ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Air Conditioners ◽  
Heating And Cooling ◽  
The Creation ◽  
Air Conditioning Systems

Centralized air conditioning systems are widely used in buildings at present. In these conditioners, the outside air gets required temperature, humidity, purity, and other features, necessary for creating comfort microclimate in inside areas of houses, and by the help of fans and air ducts the processed air moves to all rooms of a building. As a result, the creation and maintenance of comfort conditions in buildings become complicated and expensive activity. From this point of view, it is becoming more expedient to install local air conditioners in each room instead of single central one for the whole building. For this reason new local air conditioner is developed.

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