The Experts below are selected from a list of 10407 Experts worldwide ranked by ideXlab platform
Yang Yao - One of the best experts on this subject based on the ideXlab platform.
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experimental study on the performance of a multi functional domestic Air Conditioner with integrated water heater
Applied Thermal Engineering, 2017Co-Authors: Jiankai Dong, Yang Yao, Yiqiang Jiang, Xinran ZhangAbstract:Abstract The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic Air Conditioner, this paper experimentally studied a multi-functional domestic Air Conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic Air Conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.
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an experimental and theoretical study on an injection assisted Air Conditioner using r32 in the refrigeration cycle
Applied Energy, 2017Co-Authors: Bingbing Dong, Lin Cao, Jijin Wang, Runxin Shang, Yang YaoAbstract:Abstract An Air-Conditioner (AC) that uses refrigerant R32 assisted with one-phase vapor injection shows high energy efficiency and low discharge temperature in the heat-pump cycle, but the performance is not satisfactory in the refrigeration cycle. In this study, an improved injection cycle consisting of one-phase vapor injection mode and two-phase injection mode is proposed and integrated into an AC using R32, which is now referred to as an advanced injection-assisted Air-Conditioner (IAC). Through an experimental and theoretical study, an optimal injection duration of 8 s is attained for maximizing the refrigeration potential of the IAC. Furthermore, in an entire day–night cycle, both the cooling capacity and energy efficiency ratio (EER) of the IAC within the two-phase injection cycle are enhanced by 25% and 32%, respectively, compared with those of a noninjection-assisted AC. Moreover, two-phase injection offers the highest exergetic efficiency, approximately 50% or more in the refrigeration cycle, exhibiting remarkable thermodynamic performance of the IAC. In addition, compared to the conventional AC using R410A, the IAC using R32 within a two-phase injection cycle demonstrates reasonable payback performance and substantial reduction in carbon dioxide and sulfur dioxide emissions in the refrigeration cycle.
Jun Dong - One of the best experts on this subject based on the ideXlab platform.
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domestic Air Conditioner and integrated water heater for subtropical climate
Applied Thermal Engineering, 2003Co-Authors: T T Chow, Gang Pei, Jun DongAbstract:The technology of using a heat pump for space conditioning and domestic hot water heating in residences has been developed for half a century. The earlier Air-to-water heat pumps and water-heating heat pumps suffered from drawbacks like high costs, unreliable operation, and inflexible applications. They were not well positioned in the market to attract customers. This paper introduces a novel Air-conditioning product that can achieve the multi-functions with improved energy performance. The basic design principles and the laboratory test results are presented. The results showed that by incorporating a water heater in the outdoor unit of a split-type Air-Conditioner so that space cooling and water heating can take place simultaneously, the energy performance can be raised considerably.
Xinran Zhang - One of the best experts on this subject based on the ideXlab platform.
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experimental study on the performance of a multi functional domestic Air Conditioner with integrated water heater
Applied Thermal Engineering, 2017Co-Authors: Jiankai Dong, Yang Yao, Yiqiang Jiang, Xinran ZhangAbstract:Abstract The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic Air Conditioner, this paper experimentally studied a multi-functional domestic Air Conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic Air Conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.
Shahab Alizadeh - One of the best experts on this subject based on the ideXlab platform.
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performance of a solar liquid desiccant Air Conditioner an experimental and theoretical approach
Solar Energy, 2008Co-Authors: Shahab AlizadehAbstract:Abstract In this paper the results of testing a solar liquid desiccant Air Conditioner (LDAC) in the tropical climate of Queensland, Australia have been presented. The system uses polymer plate heat exchanger (PPHE) for dehumidification/indirect evaporative cooling, and a cooling pad as the direct evaporative cooler for the dry Air leaving the PPHE. Lithium chloride, which is an effective desiccant in Air dehumidification, was used in the experiments and a scavenger Air regenerator concentrates the dilute solution from the dehumidifier using hot water from flat plate solar collectors. The data obtained from performance monitoring of the solar LDAC operating on a commercial site in Brisbane was compared with a previously developed model for the PPHE. The comparison reveals that good agreement exists between the experiments and model predictions. The inaccuracies are well within the measuring errors of the temperature, humidity and the Air and solution flow rates. The above tests further indicate a satisfactory performance of the unit by independently controlling the Air temperature and humidity inside the conditioned space. In order to prevent carryover of the solution particles into the environment, eliminators are used at outlet of the absorber unit and the regenerator. An alternative method in preventing the carryover is the use of indirect cooling, in which the supply Air does not contact the solution. The method can be used to produce potable water from the atmospheric Air in remote areas. The liquid desiccant system can be used in the HVAC industry, either as a packaged roof-top Air Conditioner, or as an Air handler unit for commercial applications. The system could also be used for space heating in winter due to the property of desiccants to provide heat when wetted.
Eric Kozubal - One of the best experts on this subject based on the ideXlab platform.
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a zero carryover liquid desiccant Air Conditioner for solar applications
Solar Energy, 2006Co-Authors: Andrew Lowenstein, Steven Slayzak, Eric KozubalAbstract:A novel liquid-desiccant Air Conditioner that dries and cools building supply Air has been successfully designed, built, and tested. The new Air Conditioner will transform the use of directcontact liquid-desiccant systems in HVAC applications, improving comfort and indoor Air quality, as well as providing energy-efficient humidity control Liquid-desiccant Conditioners and regenerators are traditionally implemented as adiabatic beds of contact media that are highly flooded with desiccant. The possibility of droplet carryover into the supply Air has limited the sale of these systems in most HVAC applications. The characteristic of the new Conditioner and regenerator that distinguishes them from conventional ones is their very low flows of liquid desiccant. Whereas a conventional Conditioner operates typically at between 10 and 15 gpm (630 and 946 ml/s) of desiccant per 1000 cfm (0.47 m 3 /s) of process Air, the new Conditioner operates at 0.5 gpm (32 ml/s) per 1000 cfm (0.47 m 3 /s). At these low flooding rates, the supply Air will not entrain droplets of liquid desiccant. This brings performance and maintenance for the new liquid-desiccant technology in line with HVAC market expectations. Low flooding rates are practical only if the liquid desiccant is continually cooled in the Conditioner or continually heated in the regenerator as the mass exchange of water occurs. This simultaneous heat and mass exchange is accomplished by using the walls of a parallel-plate plastic heat exchanger as the Air/desiccant contact surface. Compared to existing solid- and liquid-desiccant systems, the low-flow technology is more compact, has significantly lower pressure drops and does not “dump” heat back onto the building’s central Air Conditioner. Tests confirm the high sensible and latent effectiveness of the Conditioner, the high COP of the regenerator, and the operation of both components without carryover.