Enthalpy and Exergy Analysis of Domestic Desiccant Air Conditioner With Cooling Dehumidification and Heating Humidification Using Process Simulator

2011 ◽  
Author(s):  
Shun Hirano ◽  
Yoshinori Hisazumi ◽  
Tsukasa Hori ◽  
Tsutomu Wakabayashi ◽  
Akira Kishimoto ◽  
...  
Keyword(s):  
Exergy Analysis ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Evaporative Cooler ◽  
Humidified Air ◽  
Process Simulator ◽  
Exergy Analyses ◽  
Direct Evaporative Cooler ◽  
Exergy Losses

To popularize the use of desiccant air conditioners in residences, a system that can supply cooled and dried air in summer as well as heated and humidified air in winter is proposed. An evaporative cooler that affords an increase in cooling capacity and the amount of humidification is used in this system. The results of the enthalpy and exergy analyses, performed using a process simulator, showed that significant exergy losses occurred at the blower, heater, and desiccant rotor. In addition, exergy loss occurred at the direct evaporative cooler in heating humidification. Furthermore, it was found that there exists an optimal water temperature that yields peak exergy efficiency from the desiccant rotor.

Exergy Analysis on a Split-Type Conditioner Using Ejector as an Expansion Device

2014 ◽  
Vol 699 ◽  
pp. 828-833 ◽  
Author(s):  
Sumeru ◽  
Markus ◽  
Farid Nasir Ani ◽  
Henry Nasution
Keyword(s):  
Performance Improvement ◽  
System Performance ◽  
Air Conditioning ◽  
Exergy Analysis ◽  
Energy Savings ◽  
Air Conditioner ◽  
Total Energy Consumption ◽  
Air Conditioning System ◽  
Air Conditioners ◽  
Exergy Losses

Air conditioning system consumes approximately 50% of the total energy consumption of buildings. Split-type air conditioner is the most widely used in residential and commercial buildings. As a result, enhancement on the performance of the air conditioners will yield a significant energy savings. The use of ejector as an expansion device on the split-type air conditioners is one method to increase the system performance. Exergy analysis on a split-type air conditioner uses an ejector as an expansion device at room and outdoor temperatures of 24 °C and 34 °C, respectively, yielded the percentage of exergy reduction up to 40.6%. Also, the exergy losses on in the compressor had the highest impact on the performance improvement of the split-type air conditioner.

Test Analysis of Performance of the Direct Evaporative Cooling Air Conditioners

2013 ◽  
Vol 827 ◽  
pp. 298-301
Author(s):  
Jian Zhang
Keyword(s):  
Relative Humidity ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Cooling Efficiency ◽  
Air Conditioner ◽  
Test Analysis ◽  
Air Conditioners ◽  
Direct Evaporative Cooling ◽  
Cooling Air ◽  
Analysis Of Performance

The direct evaporative cooling conditioner experimental research is carried out in this paper. Analyze the influence of inlet air dry ball temperature and relative humidity to air conditioner cooling capacity and cooling efficiency, which has certain guiding significance to improve the direct evaporative cooling air conditioner performance.

Impact on Overall Efficiency of Component Efficiency Increases for an Existing Thermal Electrical Generating Station

2002 ◽  
Author(s):  
Marc A. Rosen
Keyword(s):  
Exergy Analysis ◽  
Large Temperature ◽  
Efficiency Improvement ◽  
Combustion Heat ◽  
Component Efficiency ◽  
Pertinent Information ◽  
Electrical Generator ◽  
Overall Efficiency ◽  
Exergy Analyses ◽  
Exergy Losses

Most electrical generating utilities are striving to improve the efficiencies of their existing thermal electric generating stations, many of which are old. Exergy methods have been shown to provide meaningful insights that can assist in increasing the efficiency of conventional coal-to-electricity technologies. Here, exergy analysis is used to assess measures for improving the efficiencies of coal-fired electrical generating stations. This scope of the study is limited to minor practical improvements, which can be undertaken with limited effort and cost and are not overly complex. The plant considered is the coal-fired Nanticoke Generating Station (GS) in Ontario, Canada. The findings suggest that the results of exergy analyses should be used, along with other pertinent information, to guide efficiency improvement efforts for thermal generating stations. Also, efficiency improvement efforts should focus on plant components responsible for the largest exergy losses: the steam generator (where large losses occur from combustion heat transfer across large temperature differences), the turbines, the electrical generator and the transformer. Possible improvements in these areas should be assessed in conjunction with other criteria, and other components should be considered where economically beneficial improvements can be identified.

Performance Study of the Household Air Conditioner under Extreme Climate Conditions

2013 ◽  
Vol 860-863 ◽  
pp. 1607-1611
Author(s):  
Xin Zhao ◽  
Wei Ting Jiang ◽  
Wei Guo Pan ◽  
Jun Li ◽  
Su Liu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Outdoor Temperature ◽  
Performance Study ◽  
Climate Conditions ◽  
Air Conditioners ◽  
Extreme Climate ◽  
Outdoor Climate ◽  
Future Direction

This paper used physical modeling method to simulate the running state of each component of the air conditioner, got the ideal conditions of air conditionor energy consumption model and then calibrated and corrected the model of the air conditioner energy consumption by the experimental data. After utilizing the model for the performance analysis of the actual air conditioner, it was found that the extreme outdoor climate would affect the performance of the air conditioner. In summer, the electricity required to produce the same amount of cooling capacity will be 210% compared with 30°C of outdoor temperature, when the outdoor temperature is 50 °C; In winter, the drop of outdoor temperature will seriously impact on the energy efficiency of air conditioner, when the outdoor temperature is-5°C the electricity required to produce the same amount of cooling capacity will be 150% compared with 10 °C of outdoor temperature. It is of great significance that the results shown in this research contributes to the analysis of air conditioner in extreme conditions, and amended energy consumption of the model can not only forecast the performance of household air conditioners under the extreme climate but also indicate the future direction of air conditionersdesign and improvement.

scholarly journals Energy Efficiency Study, Comparing, Commercial Grade Propane/Butane Blend; Refrigerant Grade Propane and Chlorodifluoromethane (CHClF2), Investigated in a Psychrometric Chamber

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Z. Zakaria ◽  
D. Veerasamy ◽  
J. H. Koh
Keyword(s):  
Energy Efficiency ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Liquefied Petroleum Gas ◽  
Air Conditioners ◽  
Commercial Grade ◽  
Propane Butane

The current use of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) as refrigerants will be phaseout and phasedown. Hydrocarbon (HC) refrigerants were introduced as potential replacements. These refrigerant grade hydrocarbons namely propane (R 290) and isobutane (R 600a) were on sale at premium prices. As Malaysia has capabilities to produce LPG, a study was conducted to find out the suitability of commercial liquefied petroleum gas (LPG) to be used as refrigerant. This study compares the efficiencies and cooling capacities of commercial grade LPG to refrigerant grade propane (C3H8) and chlorodifluoromethane (CHClF2) (R 22) in a split unit air conditioner installed in a psychrometric chamber. Results of experiments indicated that the commercial blends in the ratio of 80% propane and 20% butane provided the highest efficiency, but had the lowest cooling capacities; in contrast, the imported refrigerant grade propane despite value being purer, was not reflected in term of its efficiency; recorded the lowest. CHClF2 provided the highest efficiency and cooling capacity. LPG has the potential to replace R22 in split air conditioners despite losing 10 % in cooling capacities but instead gained 2.6% in energy efficiencies. 

scholarly journals Performance Investigation of Direct Evaporative Cooling in Major Cities of Iraq

2015 ◽  
Vol 10 (2) ◽  
Keyword(s):  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Climate Data ◽  
Direct Evaporative Cooling ◽  
Simulation Results ◽  
Evaporative Cooler ◽  
Direct Evaporative Cooler

The cities of Baghdad, Basrah, and Mousl are the major cities in the middle, southern and northern parts of Iraq, respectively. In this paper, TRNSYS model is investigated to study the performance of direct evaporative cooler (DEC) in these cities. Based on the hourly climate data of each month in Typical Meteorological Year (TMY), the period of 1st of June to 31th of August is used to estimate the performance of DEC in terms of evaporative supply temperature and cooling capacity. The simulation results show that the performance of DEC is capable of providing comfort conditions in Baghdad and Mosul by lowering supply air dry bulb temperature below the design condition (24ºC) up to 2ºC in June and July and 1.5ºC in August. In addition, the maximum cooling capacity of DEC is obtained in July about (3617, 3417 and 3160) kW for Baghdad, Mosul and Basrah, respectively.

scholarly journals The Influence of Room and Ambient Temperatures of Exergy Loss in Air Conditioning Using Ejector as an Expansion Device with R290 as Working Fluid

2019 ◽  
Vol 130 ◽  
pp. 01019
Author(s):  
Kasni Sumeru ◽  
Pratikto Pratikto ◽  
Andriyanto Setyawan ◽  
Adenkule Moshood Abioye
Keyword(s):  
Air Conditioning ◽  
Exergy Analysis ◽  
Numerical Approach ◽  
Cooling Capacity ◽  
Exergy Loss ◽  
Working Fluid ◽  
Air Conditioner ◽  
Ambient Temperatures ◽  
Environmental Friendly ◽  
Natural Refrigerant

This paper presents a numerical approach on exergy loss in an air conditioner (A/C) using ejector asexpansion device with R290 (propane) as working fluid. R290 is a natural refrigerant and environmental friendly, recommended by many researchers as a substitute for R22. In the numerical approach, exergy analysis was carried out on an A/C with cooling capacity of 2.4 kW, and the room and the ambient temperatures were varied from 18 °C to 26 °C and 30 °C to 34 °C respectively. The results show that the total exergy loss in an air conditioner using ejector as an expansion device is lower than that of using conventional as an expansion device. In addition, exergy analysis shows that thegradients of increment of total exergy loss due to increase in the ambient temperature are constant, that is 0.003 for the five different room temperatures, namely 18 °C, 20 °C, 22 °C, 24 °C and 26 °C.

Experimental and Numerical Study of Cooling Performance of Air Conditioner Using R32/CO2 Refrigerant Mixture

2019 ◽  
Vol 27 (02) ◽  
pp. 1950019
Author(s):  
Pushpak Doiphode ◽  
Vignesh Lakshmanan ◽  
Indraneel Samanta
Keyword(s):  
Ozone Depletion ◽  
Numerical Study ◽  
Cooling Capacity ◽  
Air Conditioner ◽  
Total Energy Consumption ◽  
Cooling Performance ◽  
Air Conditioners ◽  
Refrigerant Mixture ◽  
Consumption Energy ◽  
Analysis Of Performance

Conventional refrigerants such as chlorofluorocarbons and hydrochlorofluorocarbons have high values of global warming potential (GWP) and ozone depletion (ODP). HVAC&R engineers and designers are exploring alternate refrigerants having low ODP and GWP. At present, R32 refrigerant is being considered as an alternative to the conventional refrigerants in domestic air conditioners by many manufacturers and countries. This study analyzes the steady-state cooling performance of a split air conditioner using R32(CH2F2) and R32/CO2 (Carbon Dioxide) mixture having lower GWP. The performance of the air conditioner with R32 and four different compositions of R32/CO2 mixture is studied experimentally and numerically. A comparative analysis of performance characteristics such as cooling capacity, total energy consumption, energy efficiency, operating pressures and temperatures is presented in this study.

scholarly journals The Effect of Refrigerant Charge on the Performance of a Split-Unit Type Air Conditioner Using R22 Refrigerant

2018 ◽  
Vol 225 ◽  
pp. 02011
Author(s):  
Mohd Hazwan Yusof ◽  
Sulaiman Mohd Muslim ◽  
Muhammad Fadhli Suhaimi ◽  
Hassan Ibrahim ◽  
Azizuddin Abdul Aziz ◽  
...  
Keyword(s):  
Cost Saving ◽  
Cooling Capacity ◽  
Optimal Operation ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Unit Type ◽  
Small Capacity

Numerous air conditioners are running without a proper refrigerant charge due to leakage and improper charging during installation. Therefore, there is a need to understand the performance of the air conditioner if it is not properly charged for the means of optimal operation and cost saving. This study is focusing on the usage of a used small capacity split-unit type air conditioner using R-22 refrigerant. The objective is to study the condenser performance over a variation of refrigerant charges. From the results, it is clear that the optimum refrigerant charge is 100%. The highest cooling capacity and COP were 3,330 J/s and 3.05 respectively.

scholarly journals Exergy Analysis of Fluidized Desiccant Cooling System

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 757 ◽  
Author(s):  
Zbigniew Rogala ◽  
Piotr Kolasiński
Keyword(s):  
Exergy Analysis ◽  
Cooling System ◽  
The Other ◽  
Coefficient Of Performance ◽  
Exergy Destruction ◽  
Regenerative Heat ◽  
Design And Implementation ◽  
Air Cooler ◽  
Evaporative Cooler ◽  
Direct Evaporative Cooler

One of the main challenges in the design and implementation of fluidized desiccant cooling (FDC) systems is increasing their low COP (coefficient of performance). Exergy analysis is one of the tools especially suitable for improvement and optimization of FDC systems. The improvement of performance is impossible as long as the main sources of exergy destruction are not identified and evaluated. In this paper, the exergy analysis was applied in order to identify these components and processes of the FDC system that are mainly responsible for exergy destruction. Moreover, the exergy efficiency of a simple fluidized desiccant cooler was determined. The results showed that fluidized beds and regenerative heat exchanger were the main exergy destruction sources with a 32% and 18% share of total exergy destruction, respectively. On the other hand, the direct evaporative cooler and air cooler placed after the desorbing fluidized bed were characterized by the lowest exergy efficiencies. This work contributes to better understanding of FDC operation principles and improvement of the performance of FDC technology.

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