scholarly journals Critical Review on the Developments and Future Aspects of Adsorption Heat Pumps for Automobile Air Conditioning

2018 ◽  
Vol 8 (11) ◽  
pp. 2061 ◽  
Author(s):  
Shinnosuke Maeda ◽  
Kyaw Thu ◽  
Tomohiro Maruyama ◽  
Takahiko Miyazaki
Keyword(s):  
Energy Density ◽  
Critical Review ◽  
Air Conditioning ◽  
Waste Heat ◽  
Environmental Issues ◽  
Heat Pumps ◽  
Adsorption Heat ◽  
Vapour Compression ◽  
Adsorption Systems ◽  
Automobile Air Conditioning

Emission and heat rejection from automobiles are largely responsible for urban environmental issues. Adsorption systems driven by engine waste heat exhibit huge potential to meet the demand for cabin thermal comfort while improving fuel economy. However, the mechanical vapour compression (MVC) systems are still the undisputed champions in automobile air conditioning. This paper provides a critical review on the development and progress of adsorption heat pumps specifically for automobile air conditioning. In doing so, some of the progress and development in land-based adsorption chillers (heat pump), which are not realistically relevant to automobile adsorption systems, are explicitly excluded. Matching the energy density, durability, and reliability of the MVC systems remain major hurdles. The importance of improving the energy density based on the overall system weight or volume, real-world tests under various driving modes and durability aspects are discussed.

scholarly journals Feasibility Study of Solar Adsorption Technologies for Automobile Air-Conditioning

Solar Energy ◽  
2005 ◽  
Author(s):  
M. O. Abdullah ◽  
S. L. Leo
Keyword(s):  
Feasibility Study ◽  
Ozone Depletion ◽  
Air Conditioning ◽  
Waste Heat ◽  
Environmentally Benign ◽  
Adsorption System ◽  
Adsorption Refrigeration ◽  
Adsorption Technology ◽  
Cooling Loads ◽  
Automobile Air Conditioning

An adsorption system driven by solar heat or waste heat can help to eliminate the use of ozone depletion substances, such as chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs). In recent years, adsorption system has witnessed an increasing interest in many fields due to the fact that this system is quiet, long lasting, cheap to maintain and environmentally benign. Although adsorption system is not commonly used for automobile air conditioning, adsorption-cooled mini-refrigerators have been marketed for recreational transports (motor homes, boats, etc). Hence, there exists a need for a creative design and innovation to allow adsorption technology to be practical for air conditioning in automobile. The objective of this paper is to present a comprehensive review on the past efforts in the field of solar adsorption refrigeration systems and also the feasibility study of this technology for automobile airconditioning purpose. It is a particularly an attractive application for solar energy because of the near coincidence of peak cooling loads with the available of solar power.

Use of the Linear Driving Force Approximation in Adsorption Heat Pump and Chiller Modeling

2009 ◽  
Author(s):  
Alex Raymond ◽  
Srinivas Garimella
Keyword(s):  
Mass Transfer ◽  
Driving Force ◽  
Waste Heat ◽  
Heat Pumps ◽  
Adsorption Heat ◽  
Activated Carbon Fiber ◽  
Fickian Diffusion ◽  
Half Cycle ◽  
Linear Driving Force ◽  
Adsorption Heat Pump

Adsorption heat pumps and chillers can utilize solar or waste heat to provide space conditioning, process heating or cooling, or energy storage. In these devices, accurate modeling of intraparticle adsorbate mass transfer is an important part of predicting overall performance. The linear driving force (LDF) approximation is often used for modeling intraparticle mass transfer in place of the more detailed Fickian diffusion (FD) equation for its computational simplicity. This paper directly compares the adsorbate contents predicted by the conventional LDF approximation, an empirical LDF approximation proposed by El-Sharkawy et al. [1], and the FD equations for cylindrical adsorbent fibers such as activated carbon fiber (ACF). The conditions under which the LDFs agree with the FD equation are then evaluated. It is shown that for a given working pair, agreement between the LDF and FD equations is affected by the diffusivity, particle radius, half-cycle time, initial adsorbate content, and equilibrium adsorbate content. The maximum possible error in adsorbate content predicted by the LDF approximation compared with the FD solution is then calculated for the ACF (A-20)-ethanol working pair. Although the maximum error will be different for other cases, the technique used in this paper can be reproduced to determine the greatest possible LDF error for any working pair.

scholarly journals Sustainable Cooling Research Using Activated Carbon Adsorbents and Their Environmental Impact

2017 ◽  
pp. 186-221 ◽  
Author(s):  
Ahmed M. Elsayed ◽  
Hassan J. Dakkama ◽  
Saad Mahmoud ◽  
Raya Al-Dadah ◽  
Waseem Kaialy
Keyword(s):  
Activated Carbon ◽  
Energy Consumption ◽  
Waste Heat ◽  
High Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Adsorption Refrigeration ◽  
Recent Developments ◽  
Air Conditioning Systems ◽  
Vapour Compression

Conventional vapour compression system is one of the most utilized cycles in refrigeration and air conditioning systems, due to its compact size, the relatively low running cost, the high coefficient of performance and the wide range of the operating temperatures. Nevertheless, the system suffers from the high initial cost and the high-energy consumption. Unlike the vapour compression cycle, adsorption heat pumps have the advantage of utilizing waste heat reducing the energy consumption and the carbon emissions. Activated carbon is a porous adsorbent material that can be efficiently used in low temperature adsorption refrigeration systems. This chapter reviews the recent developments in the compact adsorption cooling systems using activated carbon regarding the enhancement of the material properties, the design of the sustainable adsorption systems and their environmental and cost perspectives.

scholarly journals Chillers of air-conditioning systems: An overview

2020 ◽  
Vol 27 (3) ◽  
pp. 113-127
Author(s):  
Michael Kwok Hi Leung ◽  
Chi Yan Tso ◽  
Wei Wu ◽  
Zhanying Zheng ◽  
Jingyu Cao
Keyword(s):  
Environmental Performance ◽  
Air Conditioning ◽  
Waste Heat ◽  
Technical Information ◽  
Air Conditioning System ◽  
Compression Cycle ◽  
Different Types ◽  
Air Conditioning Systems ◽  
System Configurations ◽  
Vapour Compression

In tropical and subtropical regions, air-conditioning commonly consumes the most energy in buildings. The chillers used in existing air-conditioning systems are largely based on thermodynamic vapour compression cycle because the cycle is highly effective, efficient and practical. Moreover, the system installation and operation are convenient when grid electricity is available. Popular vapour compression chiller types include air-cooled, water-cooled, seawater-cooled and oil-free chillers. In addition, thermal-driven absorption and adsorption chillers have become available in the market. Viable sources of thermal energy input include fuel combustion, renewable solar energy, waste heat, and so on. This paper provides an overview of different types of chillers and system configurations in terms of mechanisms, characteristics, energy efficiency, environmental performance and costs. The technical information and comparisons should help engineers select the chiller type in air-conditioning system design for achieving high sustainability.

Hybrid Liquid Desiccant/Vapour Compression Air-Conditioning Systems: A Critical Review

2008 ◽  
Author(s):  
Roza I. Christodoulaki ◽  
Emmanuil D. Rogdakis ◽  
Irene P. Koronaki
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Electrical Energy ◽  
Hot Water ◽  
Vapor Compression ◽  
Solar Thermal Energy ◽  
Liquid Desiccant ◽  
Design Variables ◽  
Air Conditioning Systems ◽  
Vapour Compression

Hybrid Liquid Desiccant Cooling / Vapour Compression Systems is an environmentally friendly technology used to condition the internal environment of buildings. In contrast to conventional vapor compression air conditioning systems, in which the electrical energy drives the cooling cycle, desiccant cooling is heat driven; therefore, hybrid LDC/VCS have the potential to utilise cleaner energy sources such as gas, hot water, waste heat or solar thermal energy. In hybrid LDC/VCS, the latent cooling load is handled by the desiccant dehumidifier, while the sensible is handled by a conventional VCS. Hybrid systems combining liquid desiccant cooling with Vapor Compression Systems, Vapor Absorption Systems and Solar Collectors use less electrical energy compared to conventional air-conditioning alone, while these savings rise as the latent load increases. Unlike other surveys on desiccant cooling, this review focuses on a detailed coverage of the hybrid LDC/VC systems. Commonly used liquid desiccants are compared towards their physical properties. Hybrid LDC/VCS employing various components and features are summarized, while different system configurations are schematically presented. Key factors for the hybrid system performance are the desiccant material, the design variables and the conduction of experiments prior to operation.

scholarly journals Development and Testing of Novel Applications for Adsorption Heat Pumps and Chillers

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 615
Author(s):  
Xavier Jobard ◽  
Pierryves Padey ◽  
Martin Guillaume ◽  
Alexis Duret ◽  
Daniel Pahud
Keyword(s):  
Energy Efficiency ◽  
Industrial Waste ◽  
Waste Heat ◽  
District Heating ◽  
Heat Pumps ◽  
Adsorption Heat ◽  
Simplified Model ◽  
Heating And Cooling ◽  
Adsorption Heat Pump ◽  
Industrial Waste Heat

This work aims at the development and the experimental characterization of new applications for adsorption heat pumps and chillers driven by industrial waste heat or renewable sources that can provide heating and/or cooling. Adsorption technologies offer the advantage of providing heating and cooling from low temperature sources below 100 °C without using refrigerant with high Global Warming Potential and with very low electricity consumption. Therefore, the technology enables the use of large untapped heat sources, increasing the energy efficiency of the heating and cooling sector with very limited impact on the environment. Several applications were investigated numerically for Switzerland using a simplified model of an adsorption heat pump. Four scenarios were identified as interesting: (1) the valorization of low-grade industrial waste heat in district heating networks, (2) energy efficiency improvement of district heating substations, (3) an autonomous adsorption heat pump with a wood pellets burner and (4) cooling applications. These scenarios were experimentally validated with a laboratory test of a commercial silica gel/water machine. Results show that there is a gap of up to 40% between the prediction of the simplified model and the experimental results. Therefore, there is huge potential to improve the performances of this commercial unit for these applications.

Analysis of Heat Pipe Heat Exchanger (HPHE) For Waste Heat Recovery from an Air Conditioning System

2007 ◽  
Vol 2 (3) ◽  
pp. 86-95
Author(s):  
R. Sudhakaran ◽  
◽  
V. Sella Durai ◽  
T. Kannan ◽  
P.S. Sivasakthievel ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Air Conditioning ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Air Conditioning System ◽  
Pipe Heat

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

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