scholarly journals Performance assessment of a solar assisted desiccant cooling system

2014 ◽  
Vol 18 (2) ◽  
pp. 563-576 ◽  
Author(s):  
Antonio Gagliano ◽  
Francesco Patania ◽  
Francesco Nocera ◽  
Aldo Galesi
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Electricity Consumption ◽  
Primary Energy ◽  
Solar Irradiation ◽  
Cooling Load ◽  
Simulation Data ◽  
Direct Flow ◽  
And Performance ◽  
Solid System

The use of solar energy to drive cooling applications, such as air conditioning is attractive since the cooling load has a high coincidence with the availability of solar irradiation. Combination of solar thermal and cooling has a high potential to reduce the electricity consumption of conventional air conditioning. This work delivers a description of solar desiccant solid system (DECs) and presents results of tests and performance analysis. The overall cooling efficiency is evaluated using simulation data typical of Mediterranean Region. In this context the autonomous operations both of a solar desiccant system (DEC) and an absorption refrigerant (AR) chillers powered by direct-flow vacuum-tube collectors are investigated. It is found out that the DEC system can achieve a primary energy saving (PES) of around 40%, compared to an AR and of around 150% compared to a conventional vapour compressor refrigerator (VCR).

scholarly journals Optimal Design of Integrated Chiller Capacity with Ice Thermal Storage for Commercial Buildings through Cooling System Cascade Analysis

2020 ◽  
Vol 10 (2) ◽  
pp. 165-175
Author(s):  
Muhammad Ikhwan Zamhuri ◽  
Haslenda Hashim ◽  
Ho Wai Shin
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Storage System ◽  
Electricity Consumption ◽  
Thermal Storage ◽  
Commercial Buildings ◽  
Optimal Size ◽  
Cooling Load ◽  
Air Conditioning System ◽  
Cascade Analysis

Chilled water air conditioning system is used to supply cooling systems in large capacity for industrial processes and commercial buildings. Air conditioners contribute more than 60 percent of electricity consumption in buildings. District Cooling System (DCS) technology comprises a central chiller plant which provides advantage compared to local air conditioning system. It has higher efficiency, uses less power in system operation, allows more usable space in buildings, and can be operated with minimum manpower while handling same amount of cooling load. The integration of a chiller with ice thermal storage (ITS) offers more operational flexibility while reducing space cooling expenses. This paper presents a systematic framework for design and operation of District Cooling Plant (DCP) comprising an integrated chiller and ice thermal storage system. The Cooling System Cascade Analysis (COSCA) based on pinch analysis is constructed to determine the chiller optimal size and ice thermal storage capacity. The District Cooling System configuration for this study comprises a cooling tower, chiller (centrifugal, variable centrifugal, glycol) and ice thermal storage system. The application of this technique to fulfil 66,284 refrigerant tonne hour (RTH) cooling load demand from commercial buildings reveals the optimal capacity of the chiller is 3068.91 refrigerant tonne (RT), ice tank rating at 989 refrigerant tonne (RT) and ice tank capacity is 9892.75 refrigerant tonne hour (RTH).

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.

scholarly journals Experimental Study to Performance Improvement of Vapor Compression Cooling System Integrated Direct Evaporative Cooler and Condenser

2018 ◽  
Vol 215 ◽  
pp. 01017
Author(s):  
Arfidian Rachman ◽  
Lisa Nesti
Keyword(s):  
Energy Use ◽  
Cooling System ◽  
Electricity Consumption ◽  
Weather Condition ◽  
Heat Removal ◽  
Cooling Capacity ◽  
Cooling Power ◽  
Cooling Systems ◽  
Evaporative Cooler ◽  
And Performance

For areas with very hot and humid weather condition increased latent and sensible load are a major problem in cooling systems that will increase compressor work so that electricity consumption will also increase. Combined condenser with direct evaporate cooling will increase the heat removal process by using an evaporative cooler effect that will increase the efficiency of energy use. This paper presents the study of the use of evaporator cooling and condenser. This paper mainly calculated energy consumption in steam compression cooling systems and related problems. From the results of this study, the use of condensers with evaporative cooling, power consumption can be reduced to 46% and performance coefficient (COP) can be increased by about 12%, with 1,2 kW cooling capacity.

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.

A Novel Technique for Reducing Cooling Load of an Air Conditioning System Operating in Hot and Humid Climates

2013 ◽  
Author(s):  
Abdulghani A. Al-Farayedhi ◽  
Nasiru I. Ibrahim ◽  
P. Gandhidasan
Keyword(s):  
Relative Humidity ◽  
Air Conditioning ◽  
Cooling System ◽  
Dew Point ◽  
High Relative Humidity ◽  
Appreciable Amount ◽  
Cooling Load ◽  
Cooling Process ◽  
Air Conditioning System ◽  
June July

Cooling load is the energy needed to be removed from a space by a cooling system to provide the desired level of comfort. Large space load requires high energy from the cooling system. A new technique of reducing the cooling load using condensate to pre-cool air stream entering the evaporator of a vapor compression air-conditioning system is presented in this paper. In a cooling process, water vapor condensation normally occurs when the evaporator coil surface temperature becomes lower than the dew point temperature of the humid air entering the evaporator. The cooling process results in appreciable amount of condensate in climatic conditions with high relative humidity and temperature such as those in Dhahran, Saudi Arabia. The rate of condensate yield is calculated using actual climate data of three typical summer days of Dhahran area for the months of June, July and August. These months are the most humid and hottest during the year. Each month is represented by a typical day determined by the average of the three hottest and humid days during the same months of the past three years. It is found that the condensate obtained during night time is more than the day time because of the high relative humidity at night. The results indicate that the cooling load can be reduced up to 10 % when the air entering the evaporator is pre-cooled by 4 °C using the condensate. In addition, the daily condensate yields from the evaporator coil in June, July and August are 1.27, 0.92 and 1.31 kg/kW-CDD, respectively.

scholarly journals Freshwater production and solar disinfection of water released from the air-conditioning cooling system: an experimental investigation

2020 ◽  
Vol 5 ◽  
pp. 9 ◽  
Author(s):  
Iessa Sabbe Moosa ◽  
Laila Masoud Rashid Al-Iessi ◽  
Hussein A. Kazem
Keyword(s):  
Solar Energy ◽  
Air Conditioning ◽  
Cooling System ◽  
Irradiation Time ◽  
Gas Production ◽  
Hydrogen Gas ◽  
Solar Irradiation ◽  
Solar Disinfection ◽  
Complete Inactivation ◽  
Cooling Air

Providing drinkable water for people is one of the crux duties of any government worldwide. As long, Oman classified among countries that suffer from a shortage of water resources, therefore finding any new sources of water is considered as very substantial work. In present work, a research was carried out on a massive quantity of water that is released out from cooling air-conditioning system in humid zones in Oman as byproduct water. The results showed that the average quantity of water gained from one AC in chosen cities was about 2 L/h, 1.9 L/h, and 1.7 L/h in Muscat, Sohar, and Al-Buraimi respectively. The results exposed that the water was almost distilled water with a pH of about 7. The electrical conductivity was very low, within the range of 45 µS/cm and less. The turbidity of the tested water was low as well, in the range of about 0.6 NTU. Additionally, it was found that solar disinfection technique was very effective to inactivate the existing bacteria in the examined water. A temperature of about 43 °C can be reached after solar irradiation for 2 h with transparent bottles. While, a temperature of around 84 °C was achieved on a sunny day after 6 h of irradiation time. The significant result of the solar disinfection was that the complete inactivation of bacteria could be achieved with an irradiation period of 2–4 h, depending on the number of bacteria per unit volume and the weather state. Moreover, some of the gained water was converted into drinking water after adding some required elements, filtration and disinfection by solar energy. Also, it is strongly recommended to use the released drain-water from cooling air-conditioning systems in the electrolysis unit cells for hydrogen gas production in conjugation with solar energy.

Fault Prediction in Air-Conditioning Refrigeration System by Wavelet Transform

2012 ◽  
Vol 614-615 ◽  
pp. 428-431
Author(s):  
Jian Jun Li ◽  
Zhi Yi Wang ◽  
Dong Zheng
Keyword(s):  
Wavelet Transform ◽  
Air Conditioning ◽  
Cooling System ◽  
Electricity Consumption ◽  
Good Deal ◽  
Basic Function ◽  
Fault Prediction ◽  
Refrigeration System ◽  
Low Performance ◽  
Conditioning Room

A good deal of electricity consumption can be attributed to air-conditioning refrigeration systems. The percentage can be significantly higher if a cooling system is operating at low performance levels due to the presence of faults. The wavelet transform moves data from a time domain to a frequency domain with the wavelet as the basic function giving the localized features of the original signal in the fault detection. It is well known for its capability of treating the transient or time-related varying signals. The fault of heat load increase of the air-conditioning room can be predicted by wavelet transform through the test. Fault prediction in air-conditioning refrigeration system by wavelet transform can avoid defects of the conventional methods.

scholarly journals Feasibility of Reducing Electricity Consumption of Air Conditioning Equipment by Condenser Direct Evaporative Cooling Technology. Example of Case Study in Dubai

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1205
Author(s):  
Anatolijs Borodinecs ◽  
Kristina Lebedeva ◽  
Aleksejs Prozuments ◽  
Arturs Brahmanis ◽  
Aldis Grekis ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Electricity Consumption ◽  
Air Cooling ◽  
Additional Energy ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Cooling Technology

The use of air conditioning technology is accompanied by an increase in electricity consumption, which is linked to an intensification of fossil fuel extraction. This in turn calls for developing cooling solutions of higher energy efficiency. The aim of this study is to examine energy consumption reduction of direct evaporative cooling technology for generating cool air in hot-dry climate regions. At the initial stage, already-installed air cooling equipment with a direct evaporative cooling system was studied for the creation of two regression models of electricity consumption representing the “on” and “off” sequences. Water consumption for system operation was taken into consideration. In the following stage, inlet water temperature dependence for pre-cooling purposes for the direct evaporative cooling system was studied. A mathematical model was developed and the subsequent calculations suggested that there is no need to pre-cool water before it enters the system and therefore consume additional energy. Practical application of this study is evaluated based on the case study in Dubai. The results of this study present significant energy saving potential for system operations of the direct evaporative cooling system of approximately 122 MWh per year. The return on investment for the equipment with direct evaporative cooling in case of an office building in Dubai featuring a hot desert climate is around 4.2 years. The purpose of this study is to examine the potential advantage of air cooling equipment with direct evaporative cooling technology compared to cooling equipment without this technology. The results provide the expediency of conducting further research in this area, in particular with regards to analyzing various materials for the adiabatic precooling pads, as well as the possibility of using a newly developed metal precooling pad.

scholarly journals An overview on use of desiccant dehumidifiers in modern air-conditioning

2019 ◽  
pp. 16-31
Author(s):  
Jani DB
Keyword(s):  
Solar Energy ◽  
Air Conditioning ◽  
Heat Recovery ◽  
Waste Heat ◽  
Cooling System ◽  
Electrical Energy ◽  
Cooling Capacity ◽  
Primary Energy ◽  
Hybrid Cooling ◽  
Hot And Humid Climates

The solid desiccant based dehumidifier used in conjunction with the conventional HVAC combines the dehumidification of solid desiccant system and with the cooling capacity of the conventional air conditioning system. This hybrid cooling system provides thermal comfort to the occupants of the conditioned space. The hybrid systems main appeal lies in the fact that, it consumes much lesser high grade electrical energy as compared to the dedicated standalone traditional air conditioning systems. The electrical energy usage is possible still lower by use of primary energy sources for to supply the thermal energy needed for the desiccant regeneration. For this purpose freely available renewable solar energy or industrial waste heat can also be used for the regeneration heat source. Sometimes it is also possible to provide condenser waste heat for the part of desiccant reactivation heat supply may increase the overall performance of the system. It was also found that this cooling system with use of air to air waste heat recovery wheel performed better than without it in terms of dehumidification as well as cooling performance. The present study report important literature survey on the dehumidification potentials of desiccant integrated hybrid cooling system operating in hot and humid climates. Keywords: Hybrid air-conditioning; Rotary desiccant dehumidifier; Heat recovery wheel; Regeneration heat; Renewable solar energy; Waste heat

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