Effect of cooling water loop on the thermal performance of air conditioning system

The electrical power consumption of refrigeration equipment leads to a significant influence on the supply network, especially on the hottest days during the cooling season (and this is besides the conventional electricity problem in Iraq). The aim of this work is to investigate the energy performance of a solar-driven air-conditioning system utilizing absorption technology under climate in Baghdad, Iraq. The solar fraction and the thermal performance of the solar air-conditioning system were analyzed for various months in the cooling season. It was found that the system operating in August shows the best monthly average solar fraction (of 59.4%) and coefficient of performance (COP) (of 0.52) due to the high solar potential in this month. Moreover, the seasonal integrated collector efficiency was 54%, providing a seasonal solar fraction of 58%, and the COP of the absorption chiller was 0.44, which was in limit, as reported in the literature for similar systems. A detailed parametric analysis was carried out to evaluate the thermal performance of the system and analyses, and the effect of design variables on the solar fraction of the system during the cooling season.

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Simulation and experimental study of phase change cooling and heating wall radiation air conditioning system

E3S Web of Conferences ◽

10.1051/e3sconf/202014302044 ◽

2020 ◽

Vol 143 ◽

pp. 02044

Author(s):

Gao Chunxue ◽

Wu Songlin ◽

Lang Junqian ◽

Liu Qiuxin

Keyword(s):

Phase Change ◽

Thermal Performance ◽

Air Conditioning ◽

Field Experiments ◽

Thermal Environment ◽

Operating Conditions ◽

Operation Condition ◽

Heating Wall ◽

Air Conditioning System ◽

Winter Operation

This paper presents a case study of phase change cooling and heating wall radiant (PC-CHWR) air conditioning system application in an energy-saving renovation project in a laboratory in Wuhan, Hubei province in China. To test the thermal performance of the system, the PHOENICS software was utilized to simulate and analyse the indoor thermal environment in the laboratory under both winter and summer operating conditions. In addition, field experiments were also conducted under winter operation condition. By comparing the results between numerical simulation and field experiment, it is found that thermal performance of the PC-CHWR air conditioning system evaluated by these two evaluation methods are quite match. Moreover, the results also show that the PC-CHWR system can meet the cooling and heating load of the building within the acceptable range.

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Solar Air Conditioning Systems With PCM Solar Collectors

Solar Energy ◽

10.1115/sed2002-1040 ◽

2002 ◽

Author(s):

Jorge E. Gonza´lez ◽

Luis Humberto Alva S.

Keyword(s):

Flat Plate ◽

Thermal Performance ◽

Air Conditioning ◽

Lithium Bromide ◽

Geographical Location ◽

Solar Collectors ◽

Absorption System ◽

Air Conditioning System ◽

Graphite Composite ◽

Cooling Loads

This paper investigates the technical feasibility of using a compact, air-cooled, solar absorption air conditioning system when coupled to an innovative array of solar collectors. The particular absorption system of study is a single effect that uses lithium bromide and water as the absorbent and refrigerant fluid pair. The geographical location of interest is Puerto Rico and similar subtropical regions. The heat input to the absorption system generator is provided by an array of novels flat plate solar collectors that integrate the thermal storage component into them. The proposed collectors have a phase change material (PCM) integrated into them as a storage mechanism. The PCM-integrated solar collector eliminates the need of conventional storage tanks reducing cost and space. The present work uses a paraffin-graphite composite as the PCM to increase the conductivity of the PC matrix. The paraffin’s melting point is around 89°C that is appropriate for use in absorption systems. The mathematical model that describes the thermal process in the PCM is presented and differs from the analysis of conventional flat plate solar collectors. The proposed model for the PCM considers the temporal changes but not the spatial variations. The resulting set of equations for the fluid flow, the PCM, and the collector’s surface are solved simultaneously. Results for the collectors’ thermal performance are presented along with the effects of the composition of the PCM material. The thermal performance of an absorption machine coupled to an array of the proposed PCM’s solar collectors was investigated for nominal cooling capacities of 10.5, 14, and 17.5 kW. These cooling loads are suitable for a typical house or a small business building in Caribbean Islands. Computer simulations were conducted to evaluate the overall system’s performance when subjected to dynamic cooling loads. Within the computer model, heat and mass balances are conducted on each component of the system, including the solar collectors, the air-cooled condenser, and the air-cooled absorber. Comparisons are made with an absorption air conditioning system that uses a cooling tower with conventional flat plate collectors instead of air-cooled and PCM components. Useful information about physical dimensions of collectors, number of collectors needed, and efficiency of the overall system is presented.

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STUDY ON THERMAL PERFORMANCE OF AIR-TYPE RADIATION AIR-CONDITIONING SYSTEM

Journal of Environmental Engineering (Transactions of AIJ) ◽

10.3130/aije.82.883 ◽

2017 ◽

Vol 82 (740) ◽

pp. 883-891

Author(s):

Yuji KOHATA ◽

Chisato MATSUDA ◽

Yosuke MINO ◽

Yosuke UDAGAWA ◽

Hirofumi HAYAMA

Keyword(s):

Thermal Performance ◽

Air Conditioning ◽

Air Conditioning System

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Experimental Analysis of the Thermal Performance of a Sunspace Attached to a House with a Central Air Conditioning System

Sustainability ◽

10.3390/su10051428 ◽

2018 ◽

Vol 10 (5) ◽

pp. 1428 ◽

Cited By ~ 1

Author(s):

Qingsong Ma ◽

Hiroatsu Fukuda ◽

Myonghyang Lee ◽

Takumi Kobatake ◽

Yuko Kuma ◽

...

Keyword(s):

Thermal Performance ◽

Experimental Analysis ◽

Air Conditioning ◽

Air Conditioning System ◽

Central Air Conditioning

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Thermal Performance and Energy Consumption Analyses of R290 and R22 Refrigerants in Air-conditioning System

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/413/1/012072 ◽

2018 ◽

Vol 413 ◽

pp. 012072 ◽

Cited By ~ 2

Author(s):

Teddy I. Okolo ◽

Oluseyi O. Ajayi

Keyword(s):

Energy Consumption ◽

Thermal Performance ◽

Air Conditioning ◽

Air Conditioning System

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Evaluation of Cooling Water Storage for Liquid-Desiccant Air Conditioning System

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-39949 ◽

2014 ◽

Author(s):

Danial Salimizad ◽

Chris McNevin ◽

Stephen Harrison

Keyword(s):

Air Conditioning ◽

Electrical Power ◽

Water Storage ◽

Cooling Water ◽

Operating Conditions ◽

Coefficient Of Performance ◽

Liquid Desiccant ◽

Air Conditioning System ◽

Electrical Power Consumption ◽

Evaporative Cooling Tower

Liquid-desiccant (LD) dehumidification technology has been used to extract moisture from humid air while attempting to consume less electricity than traditional air-conditioning methods. An evaporative cooling tower (ECT) was used as a cooling device to reject the latent heat gained by the system to regenerate the desiccant solution. The performance of an ECT was evaluated both experimentally and through TRNSYS simulations to investigate optimal operating conditions. The ECT often operated in humid conditions which resulted in reduced heat rejection rates and ineffective operation. To improve performance, cooling water storage (CWS) was investigated as a way to reduce ECT usage during periods of higher ambient humidity. To undertake this study, the complete LD system, incorporating CWS, was modelled in TRNSYS for a range of typical operating conditions. The results indicated that operation of the CWS system reduced the electrical power consumption and increased the electrical coefficient of performance (COPE) of the liquid desiccant air conditioning unit system by up to 16%. The total cooling rate improved by up to 6%. Smaller gains in COPT and solar fraction were also found in the simulation results.

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