Case study and theoretical analysis of a solar driven two-stage rotary desiccant cooling system assisted by vapor compression air-conditioning

Solar Energy ◽  
2011 ◽  
Vol 85 (11) ◽  
pp. 2997-3009 ◽  
Author(s):  
Dong La ◽  
Yanjun Dai ◽  
Yong Li ◽  
Tianshu Ge ◽  
Ruzhu Wang
Keyword(s):  
Theoretical Analysis ◽  
Air Conditioning ◽  
Cooling System ◽  
Vapor Compression ◽  
Two Stage

Rechargeable Personal Air Conditioning Device

2016 ◽  
Author(s):  
Yilin Du ◽  
Jan Muehlbauer ◽  
Jiazhen Ling ◽  
Vikrant Aute ◽  
Yunho Hwang ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Cooling Capacity ◽  
Comfort Level ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
System A ◽  
Single Person ◽  
Vapor Compression Cycle ◽  
Compression Cycle

A rechargeable personal air-conditioning (RPAC) device was developed to provide an improved thermal comfort level for individuals in inadequately cooled environments. This device is a battery powered air-conditioning system with the phase change material (PCM) for heat storage. The condenser heat is stored in the PCM during the cooling operation and is discharged while the battery is charged by using the vapor compression cycle as a thermosiphon loop. The conditioned air is discharged towards a single person through adjustable nozzle. The main focus of the current research was on the development of the cooling system. A 100 W cooling capacity prototype was designed, built, and tested. The cooling capacity of the vapor compression cycle measured was 165.6 W. The PCM was recharged in nearly 8 hours under thermosiphon mode. When this device is used in the controlled built environment, the thermostat setting can be increased so that building air conditioning energy can be saved by about 5–10%.

Performance Enhancement of Solar Air Conditioners Using Hybrid Heat Rejection System

2019 ◽  
Author(s):  
Abdul Ahad Iqbal ◽  
Ali Al-Alili
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Vapor Compression ◽  
Summer Period ◽  
Cooling Systems ◽  
Hybrid Cooling ◽  
Vapor Compression Cooling ◽  
Air Conditioning Systems ◽  
Sorption Systems ◽  
Dry Cooling

Abstract The performance of air conditioning systems is highly dependent on the environmental conditions of the high pressure side, where heat is rejected to the environment. Air conditioning systems utilize dry cooling systems which often don’t provide adequate cooling during peak cooling periods, or wet cooling systems which consume a lot of water. In this study, a novel hybrid cooling system that can provide both wet and dry cooling was modelled in TRNSYS, and used to provide cooling to closed sorption air conditioning systems. The performance of these systems with the hybrid cooling system was compared to the performance of a standard vapor compression cooling system being cooled by a dry cooling system. The COPsol of the vapor compression cooling system exhibited a decrease of almost 26% during the summer period, whereas the COPsol of the sorption systems increased by around 30%. Similarly, the cooling capacity of the vapor compression cooling system dropped by almost 5%, and for the sorption systems, it increased by around 20% during the summer period.

Review on Solar Powered Desiccant Wheel Cooling System

2017 ◽  
Vol 9 (01) ◽  
pp. 31-34
Author(s):  
Khushboo Singh
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Good Alternative ◽  
Energy Utilization ◽  
Working Fluid ◽  
Low Grade ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
Desiccant Wheel ◽  
Solar Powered

Nowadays, there is still a big amount of needs in air conditioning system with environmental change and improvement of living standards. However, air conditioning system have already accounted for a large part of energy consumption in the whole society, and then how to effectively increase the energy utilization. Desiccant wheel cooling system operate on the principle of adsorption dehumidification and evaporate cooling. The system adopts natural substance as working fluid and can be driven by low grade thermal energy such as solar energy. Due to this merit, solar powered desiccant wheel cooling system has recognized as one of good alternative to conventional vapor compression air conditioning system and has obtained increasing interest in the past years. This review paper aims to summarize recent research development related to solar powered desiccant wheel cooling system and to provide information for potential application. The cooling potential of the system is based on the performance of the desiccant wheel that removes humidity from outside air to increase the potential of the humidifier.

An Analytical Comparison of Adsorption and Vapor Compression Air Conditioners for Electric Vehicle Applications

1996 ◽  
Vol 118 (1) ◽  
pp. 16-21 ◽  
Author(s):  
S. M. Aceves
Keyword(s):  
Electric Vehicle ◽  
Air Conditioning ◽  
Cooling System ◽  
Cooling Load ◽  
Air Conditioner ◽  
Vapor Compression ◽  
Adsorption System ◽  
Air Conditioners ◽  
Driving Cycles ◽  
Adsorption Systems

This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and driving cycles. The resulting adsorption systems are compared with vapor compression air conditioners that can satisfy the cooling load. The objective function is the overall system weight, which includes the cooling system weight and the weight of the battery necessary to provide energy for air conditioner operation. The system with the minimum overall weight is considered to be the best. The results show the optimum values of all the variables, as well as temperatures and amounts adsorbed, for the adsorption and desorption processes. The results indicate that, for the conditions analyzed in this paper, vapor compression air conditioners are superior to adsorption systems, not only because they are lighter, but also because they have a higher COP and are more compact.

Design and Analysis of a Continuous Operating Solar Absorption Cooling System

2010 ◽  
Author(s):  
Samved Patil ◽  
K. Max Zhang ◽  
Aditya Sahasrabuddhe ◽  
Shrewans Padhye
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Vapor Compression ◽  
Solar Absorption ◽  
Solar Cooling ◽  
Energy Demands ◽  
Vapor Absorption ◽  
Solar Absorption Cooling ◽  
Solar Cooling System ◽  
Absorption Cooling System

It has been estimated that approximately 15% of electricity produced in the whole world is utilized for refrigeration and air-conditioning applications. Increased use of air conditioning and related appliances during hot summer days leads to high electricity demands in metropolitan areas, which have to be met, in part, by generations from expensive and polluting peaking units. Thus solar cooling has great potential in reducing peaking electricity demands and the overall energy demands. We first compared the overall efficiencies of two solar cooling systems, i.e., vapor compression powered by electricity generated from photovoltaics, and vapor absorption using solar heating. Both systems matched evenly when the coefficients of performance (COP) were compared. But the payback time for vapor compression was five times longer than that for vapor absorption. Then we designed a novel solar cooling system by combining vapor absorption refrigeration (NH3-H2O absorption cycle), concentrated solar and thermal storage. The system is capable of operating autonomously at nights or two days without adequate sunlight. Heating oil is heated by a parabolic trough collector and is then stored in an insulated tank. The oil is then used to heat the refrigerants (i.e., NH3). Oil flows in two loops, one from parabolic collector to tank using thermo-syphon action and other from the tank to refrigerator using a small pump. Next, we created a model to calculate the volume of storage tank, area of solar collector for a given longitude and latitude and application. A micro-processor controlled program can be then be developed in future to control mass flow of oil in the second loop to control the output temperature.

scholarly journals Comparative Analysis for Renovation of an air Heating and Cooling System from a Romanian Administrative Building

2019 ◽  
Vol 111 ◽  
pp. 04022
Author(s):  
Calotă Răzvan ◽  
Titi Robert ◽  
Nichita Madalina ◽  
Ilie Anica ◽  
Girip Alina
Keyword(s):  
Comparative Analysis ◽  
Solid Fuel ◽  
Air Conditioning ◽  
Cooling System ◽  
Vapor Compression ◽  
Three Solutions ◽  
Fuel Wood ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Air Heating

In this paper, the authors determine the energy consumption for heating and air conditioning of an administrative building located in the second climatic area, in Romania. The heating and cooling system is provided with fan coils, and the fresh air is supplied by an AHU. The aim is to identify the best solution from 3 proposed heating and cooling systems that can be applied in order to improve the living conditions, namely: boiler with solid fuel (wood) or gas and chiller with mechanical vapor compression (VCM); reversible heat pump; boiler with solid fuel (wood) or gas and absorption chiller type LiBr-H2O driven by solar energy. The goal of the study is to select one of the three solutions which involves minimum investment and exploitation costs.

scholarly journals Simulation Analysis of the Four Configurations of Solar Desiccant Cooling System Using Evaporative Cooling in Tropical Weather in Malaysia

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
M. M. S. Dezfouli ◽  
S. Mat ◽  
G. Pirasteh ◽  
K. S. M. Sahari ◽  
K. Sopian ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Simulation Analysis ◽  
Cooling System ◽  
High Energy ◽  
Coefficient Of Performance ◽  
Humidity Ratio ◽  
Two Stage ◽  
One Stage ◽  
Temperature And Humidity ◽  
Ventilation Modes

A high demand for air conditioning systems exists in hot and humid regions because of the warm climate during the year. The high energy consumption of conventional air conditioning system is the reason for our investigation of the solar desiccant cooling system as an energy-efficient cooling system. Four model configurations were considered to determine the best configuration of a solar desiccant cooling system: one-stage ventilation, one-stage recirculation, two-stage ventilation, and two-stage recirculation. These models were stimulated for 8,760 hr of operation under hot and humid weather in Malaysia. Several parameters (i.e., coefficient of performance or COP, room temperature and humidity ratio, and the solar fraction of each system) were evaluated by detecting the temperature and humidity ratio of the different points of each configuration by TRNSYS simulation. The latent and sensible loads of the test room were 0.875 kW and 2.625 kW, respectively. By investigating the simulation results of the four systems, the ventilation modes were found to be higher than the recirculation modes in the one- and two-stage solar desiccant cooling systems. The isothermal dehumidification COP of the two-stage ventilation was higher than that of the two-stage recirculation. Hence, the two-stage ventilation mode desiccant cooling system in a hot and humid area has higher efficiency than the other configurations.

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