Experimental investigation of a ground-coupled heat exchanger combined with an air conditioner for southern India

2020 ◽  
pp. 1-7
Author(s):  
Arunkumar Damodharan ◽  
Ramu Murugan ◽  
Syath Abuthakeer
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Difficult Problem ◽  
Energy Ratio ◽  
Air Conditioner ◽  
Vapor Compression ◽  
Cooling Systems ◽  
Air Conditioners ◽  
Active Cooling ◽  
Combined Cooling

Increasing the energy ratio of an air conditioner that has a cooled air condenser is a difficult problem, particularly in areas where the temperature and humidity are very high. The efficiency of air conditioners based on standard vapor compression technology can be enhanced by combining active cooling technologies with less energy-intensive inactive cooling technologies. In this study, the cooling performance of combined cooling systems has been experimentally explored. Using four different modes of a hybrid ground-coupled heat exchanger (GCHE), an analysis was carried out to enhance the energy ratio of the active cooling system connected to the GCHE. This was achieved by using the fact that the GCHE outlet air temperature is lower than the ambient temperature and can directly supply space heating or cooling to the condenser tubes of conventional air conditioners. It was observed that with the use of a GCHE for the condenser tubes, the energy consumption of a traditional window air conditioner was reduced by 16.18%.

Evaluating Thermal Performance and Energy Conservation Potential of Hybrid Earth Air Tunnel Heat Exchanger in Hot and Dry Climate—In Situ Measurement

2013 ◽  
Vol 5 (3) ◽  
Author(s):  
Rohit Misra ◽  
Vikas Bansal ◽  
Ghanshyam Das Agarwal ◽  
Jyotirmay Mathur ◽  
Tarun Aseri
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Energy Conservation ◽  
Thermal Performance ◽  
Cooling System ◽  
Ambient Air ◽  
Passive Cooling ◽  
Air Conditioner ◽  
Cooling Systems ◽  
Active Cooling

Earth air tunnel heat exchanger is a passive cooling device with advantageous feature to reduce energy consumption in buildings. Curtailing the electricity consumption of conventional vapor compression system based air-conditioner is a major concern especially in area with hot and dry weather conditions. The performance of conventional air-conditioners can substantially be enhanced by coupling these active cooling systems with passive cooling systems. In the present research, the thermal performance and energy conservation potential of hybrid cooling system has been investigated experimentally. An attempt has been made to enhance the thermal performance of active cooling system by coupling it with earth air tunnel heat exchanger (EATHE) in two different hybrid modes. The air which comes out of EATHE is relatively cooler than the ambient air and therefore can be used either for cooling the condenser tubes of a conventional window type air-conditioner or supplying it directly to the room being conditioned. The energy consumption of conventional 1.5TR window type air conditioner is found to be reduced by 16.11% when cold air from EATHE is completely used for condenser cooling.

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.

Remote Heat Pipe Based Heat Exchanger Performance in Notebook Cooling

2005 ◽  
Author(s):  
Seyyed Khandani ◽  
Himanshu Pokharna ◽  
Sridhar Machiroutu ◽  
Eric DiStefano
Keyword(s):  
Heat Exchanger ◽  
Thermal Resistance ◽  
Heat Pipe ◽  
Cooling System ◽  
Temperature Drop ◽  
Operating Conditions ◽  
Cooling Systems ◽  
Temperature Variations ◽  
Non Linear ◽  
Condenser Temperature

Remote heat pipe based heat exchanger cooling systems are becoming increasingly popular in cooling of notebook computers. In such cooling systems, one or more heat pipes transfer the heat from the more populated area to a location with sufficient space allowing the use of a heat exchanger for removal of the heat from the system. In analsysis of such systems, the temperature drop in the condenser section of the heat pipe is assumed negligible due to the nature of the condensation process. However, in testing of various systems, non linear longitudinal temperature drops in the heat pipe in the range of 2 to 15 °C, for different processor power and heat exchanger airflow, have been measured. Such temperature drops could cause higher condenser thermal resistance and result in lower overall heat exchanger performance. In fact the application of the conventional method of estimating the thermal performance, which does not consider such a nonlinear temperature variations, results in inaccurate design of the cooling system and requires unnecessarily higher safety factors to compensate for this inaccuracy. To address the problem, this paper offers a new analytical approach for modeling the heat pipe based heat exchanger performance under various operating conditions. The method can be used with any arbitrary condenser temperature variations. The results of the model show significant increase in heat exchanger thermal resistance when considering a non linear condenser temperature drop. The experimental data also verifies the result of the model with sufficient accuracy and therefore validates the application of this model in estimating the performance of these systems.   This paper was also originally published as part of the Proceedings of the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems.

Relative Cooling: Part II — Design Considerations and Efficiency

2001 ◽  
Author(s):  
Sandu Constantin ◽  
Dan Brasoveanu
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Cooling System ◽  
High Reliability ◽  
Difficult Problem ◽  
Turbine Engines ◽  
Air Cooling ◽  
Gas Turbine Engines ◽  
Coolant Pump ◽  
Cooling Systems

Abstract Cooling systems with liquid for gas turbine engines that use the relative motion of the engine stator with respect to the rotor for actuating the coolant pump can be encapsulated within the engine rotor. In this manner, the difficult problem of sealing stator/rotor interfaces at high temperature, pressure and relative velocity is circumvented. A first generation of such cooling systems could be manufactured using existing technologies and would boost the thermal efficiency of gas turbine engines by more than 2% compared to recent designs that use advanced air-cooling methods. Later, relative cooling systems could increase the thermal efficiency of gas turbine engines by 8%–11% by boosting the temperatures at turbine inlet to stoichiometric levels and recovering most of the heat extracted from turbine during cooling. The appreciated high reliability of this cooling system will allow widespread use for aerospace propulsion.

A New Approach to Exergy Analyses of a Hybrid Desiccant Cooling System Compares to a Vapor Compression System

2011 ◽  
Vol 110-116 ◽  
pp. 2163-2169
Author(s):  
S. Khosravi ◽  
Yat Huang Yau ◽  
T.M.I. Mahlia ◽  
M.H. Saidi
Keyword(s):  
Indoor Air ◽  
Cooling System ◽  
Vapor Compression ◽  
Cooling Systems ◽  
New Approach ◽  
Compression System ◽  
Humid Condition ◽  
Economical System ◽  
Vapor Compression System ◽  
Exergy Analyses

In the recent researches HVAC with a based desiccant dehumidifier with a low ambient impact is more efficient in comparison to the traditional systems. Hybrid desiccant cooling systems can be used to control indoor air quality in buildings. This paper presents an integrated energy, entropy and exergy analysis of a hybrid desiccant cooling system compare to a compression system based on first and second laws of thermodynamic. The main objective is the use of a method called exergy costing applied to a conventional compression system that has been chosen to provide the proper conditioned air for a building in hot and humid condition. By applying the same method for the equivalent hybrid cooling system and finding the same exergy costing parameters, two systems can be in comparison to find the more economical system. The result illustrated hybrid desiccant cooling system can be providing 19.78% energy saving and 14.5% cheaper than the compression system the same capacity and lifetime. Nomenclature:

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.

Solar-Assisted Liquid Desiccant Dehumidification Using Hollow-Fiber and Parallel-Plate Membrane Dehumidifiers: Comparative Analysis

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Haitham M. Bahaidaraha ◽  
Mohand H. Mohamed ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Hollow Fiber ◽  
Parallel Plate ◽  
Cooling System ◽  
Thermal Capacity ◽  
Air Conditioner ◽  
Liquid Desiccant ◽  
Evaporative Cooling System ◽  
Mass Exchanger

In hot and humid climates, air conditioning is an energy-intensive process due to the latent heat load. A unitary air conditioner system is proposed, here, to reduce the latent heat of the humid air using a liquid desiccant followed by an evaporative cooling system. The heat liberated by the desiccant is removed by a solution to the solution heat exchanger. To restore the concentration of the liquid desiccant, the desiccant solution is regenerated by any low-temperature heat source such as solar energy. In order to make the system compact, the membrane heat exchanger is used for the dehumidifier and regenerator. This paper presents the numerical investigation of heat and mass transfer characteristics of a selected membrane dehumidifier under different climatic parameters. Membrane-based parallel-plate and hollow-fiber exchangers are used for this application. A parallel-plate heat-and-mass exchanger (contactor) is composed of a series of plate-type membrane sheets to form channels. On the other hand, hollow-fiber membranes are packed in a shell to form a shell-and-tube heat-and-mass exchanger. The two streams of both contactors are in a counter parallel flow, separated by micro-porous semi-permeable hydrophobic membranes. In this research, the equations governing the transport of heat and mass between the two streams along with the membrane effect in both contactors are solved numerically. The results are compared at different number-of-transfer units (NTU) on the airside and thermal capacity ratios. It is found that the hollow fiber is more efficient than the parallel plate.

Noise Reduction of Pressure Type Fans for Automobile Air Conditioners

1993 ◽  
Vol 115 (2) ◽  
pp. 216-220 ◽  
Author(s):  
S. Akaike ◽  
K. Kikuyama
Keyword(s):  
Noise Reduction ◽  
Computer Simulations ◽  
Noise Level ◽  
Cooling System ◽  
Laser Doppler Anemometer ◽  
Considerable Reduction ◽  
Engine Compartment ◽  
Axial Fan ◽  
Cooling Systems ◽  
Air Conditioners

Automotive air conditioners often employ a pusher-type condenser cooling system. Because the axial fan in such cooling systems is a major source of noise in the engine compartment, much effort has been directed to reducing the noise emitted by the fan. This paper clarifies the mechanism by which the fan of a pusher-type cooling system generates noise and presents ways to decrease the turbulent noise from it. Detailed studies of the flow around the fan were made using computer simulations and LDA (Laser Doppler Anemometer) measurements. A considerable reduction in the noise level of pusher-type cooling system has been achieved for different resistances without any deterioration in performance.

scholarly journals Increasing the efficiency of split type air conditioners/heat pumps by using ventilating exhaust air

2019 ◽  
Vol 100 ◽  
pp. 00006 ◽  
Author(s):  
Wojciech Cepiński ◽  
Paweł Szałański
Keyword(s):  
Energy Efficiency ◽  
Heat Exchanger ◽  
Ventilation System ◽  
Electricity Consumption ◽  
Heat Pumps ◽  
Design Solution ◽  
Simple Design ◽  
Air Conditioner ◽  
Air Conditioners ◽  
Heat Demand

The article presents the possibility of using exhaust air from ventilation system to increase the efficiency (SCOP, COP, SEER and EER) of commonly used air conditioners with the function of a heat pump. These types of devices are very popular both in residential and in public buildings. The topic discussed in the article is very important, because the widespread increase of the energy efficiency of these devices significantly influences national electricity consumption. The possibility of increasing their efficiency by directing the exhaust air from the ventilation system to the heat exchanger of the air conditioner outdoor unit has been analysed. It has been shown that the use of the simple design solution described in the article allows for a significant increase of the efficiency of these devices (seasonal efficiency even up to 35% at 100% share of exhaust air), reducing the energy consumption and increasing their capacity and operation range. By increasing the share of exhaust air it is possible to ensure year-round operation of the device and even 100% coverage of heat demand.

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