Exergy Analysis on a Split-Type Conditioner Using Ejector as an Expansion Device

2014 ◽  
Vol 699 ◽  
pp. 828-833 ◽  
Author(s):  
Sumeru ◽  
Markus ◽  
Farid Nasir Ani ◽  
Henry Nasution

Air conditioning system consumes approximately 50% of the total energy consumption of buildings. Split-type air conditioner is the most widely used in residential and commercial buildings. As a result, enhancement on the performance of the air conditioners will yield a significant energy savings. The use of ejector as an expansion device on the split-type air conditioners is one method to increase the system performance. Exergy analysis on a split-type air conditioner uses an ejector as an expansion device at room and outdoor temperatures of 24 °C and 34 °C, respectively, yielded the percentage of exergy reduction up to 40.6%. Also, the exergy losses on in the compressor had the highest impact on the performance improvement of the split-type air conditioner.

2011 ◽  
Vol 19 (01) ◽  
pp. 57-68 ◽  
Author(s):  
MIGUEL PADILLA

Commercial multiple evaporators variable refrigerant flow (VRF) HVAC systems present many advantages such as being energy saving and the capability of adjusting refrigerant mass flow rate according to the change of high rises occurrence. This paper deals with an experimental control volume exergy analysis in a VRF air conditioning system. The experimental results show that the brunt of the total exergy destroyed in the whole system occurs in the outdoor unit, where the exergy destroyed in the condenser is more important. The values of coefficient of performance (COP) obtained for the tests increase as the system reaches operational conditions imposed in every indoor unit zone. The VRF system analyzed is highly sensitive to the action of the constant speed compressor. The use of an inverter compressor improves the system performance by adjusting the power consumption according to the cooling load in the evaporators.


The objective of the study is to investigate the performance improvement in a split air conditioning system using evaporative cooling pads at ODU (outdoor unit) and to determine optimum thickness and material of the cooling pad. For this purpose experiments were conducted on 0.8 TR capacity split air conditioner charged with refrigerant R-22. For comparison experiments were performed with and without evaporative cooling pad. The effect of the different cooling pad material and thickness on the overall performance of split air conditioner is experimentally found by measuring cooling capacity and the power consumption of the system including water circulation pump. From the experimental work it is found that the cellulose cooling pad gives the best results among the selected materials. Split air conditioner coupled with cellulose cooling pad of 100 mm thickness at ODU results in to 13.8% increase in overall COP, 9.5 % reduction in power consumption and 5.1 % increase in cooling capacity at 35°C DBT and 32% relative humidity outdoor air condition.


2018 ◽  
Vol 931 ◽  
pp. 920-925
Author(s):  
Zohrab Melikyan ◽  
Naira Egnatosyan ◽  
Siranush Egnatosyan

Centralized air conditioning systems are widely used in buildings at present. In these conditioners, the outside air gets required temperature, humidity, purity, and other features, necessary for creating comfort microclimate in inside areas of houses, and by the help of fans and air ducts the processed air moves to all rooms of a building. As a result, the creation and maintenance of comfort conditions in buildings become complicated and expensive activity. From this point of view, it is becoming more expedient to install local air conditioners in each room instead of single central one for the whole building. For this reason new local air conditioner is developed.


2021 ◽  
Author(s):  
Nnamdi Cyprian Nwasuka ◽  
Nduka Nwankwojike ◽  
Uchechukwu Nwaiwu

Abstract This research presents a solar hybrid air-conditioning system with R410a refrigerant. The sole aim was to compare the performance of a solar hybrid air-conditioner with that of the conventional split-unit air-conditioning systems in the market today. From the experiments conducted, the room temperature of a solar hybrid air conditioner was found to be :27.2, 27.0, 27.0, 27.2, 27.2, 27.0, 28.0, and 29.5 while that of the conventional air conditioner was found to be:69,66,64,66,73,69,66,62 indicating that solar hybrid system had lower values in terms of room temperature than that of the split units air conditioner. Laboratory results, field assessments, and simulations clearly established that hybrid air conditioners can deliver substantial energy savings and demand reduction. Therefore, in the present study, performance evaluation of the solar hybrid system with that of the split units is used to develop approximate analytical solutions for heat transfer in boundary layer flow and heat transfer.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Dan Zhou ◽  
Haoran Wang ◽  
Cheng Zhang ◽  
Ke Sun ◽  
Hanyun Wang ◽  
...  

Solar photovoltaic driven air conditioning (PVAC) system with electricity storage is proposed as a good solution to help shifting peak load and consuming solar energy. In this paper, a grid-connected PVAC system using the TRNSYS simulation model consisting of PV panels, traditional air conditioners (TAC), power conditioning units, inverters, and grid connection equipment is proposed to investigate the economic feasibility compared with the traditional air conditioner. In the PVAC system, the electricity, firstly generated by PV panels and then stored in battery, is consumed by a DC inverter air conditioner to maintain the temperature of the room and the surplus electricity is sold to the grid. A life cycle cost comparison between PVAC system, traditional air conditioning system, and decomposed PV and air conditioning systems of three typical application cases is conducted, in which the operation conditions are based on the present circumstances of China. The results show that, in comparison with conventional air conditioners, better economic benefits can be achieved when the peak load of the air conditioning system is over a certain value. Sensitivity analysis is conducted to evaluate the effects caused by variation of economic assumptions. At last, a new operation model is proposed to achieve more benefits for the system.


2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Esmail M. A. Mokheimer ◽  
Syed Hussain ◽  
Magd DinAli Nadeem ◽  
Ahmed Ali Mahmoud Abdulrahman

A large amount of the operating costs in a building is determined by the energy requirements of its air conditioning system. The demand for more energy efficient units desired by both manufacturers and the consumers results in a dire necessity to have air conditioning units that are more energy efficient than the existing ones. In order to achieve the abovementioned features, a tool must be designed to simulate the thermal behavior of the air conditioners. In this work, a mathematical model is developed for air conditioning units and coded into a computer program to estimate the overall performance, as indicated by the unit energy efficiency ratio (EER). The main objective is to maximize the unit EER by proposing modifications or enhancements in the existing unit and to study the economics of these modifications based on the measured terms such as the energy savings and the operating cost. Finally, the effect of the proposed design modifications on the economy and environment at the national level in Saudi Arabia is estimated and presented as an example.


2020 ◽  
Vol 38 (7A) ◽  
pp. 984-991
Author(s):  
Krar M. Kuder ◽  
Hashim A. Hussein ◽  
Ali H. Numan

The present research paper is on photovoltaic air conditioning system using the direct drive method. The experimental system setup arranged in Iraq at Al-taje site at longitude 44.34 and latitude 33.432 during the summer season inside a room. The proposed off-grid system consists of an array of photovoltaic, battery used to store power, PWM (pulse width modulation) charge controller, and DC air cooler. During the examination of the system, proven success of this new type(dc air conditioner ) of client urges Iraq warm conditions as an alternative type used instead of the prevailing types of air conditioners (AC air conditioner )in Iraq which consume large amounts of electrical energy and gets a cooling system for the room full working on solar energy.                                                                                                                


The work is aimed to replace conventional refrigerants used in air cooling system with Air Cycle Machine (ACM). Commercial Air-conditioners uses the refrigerants (Freon-Gas cycle) to remove the indoor air from the room. Freon leakage causes health problems such as respiratory ailments, heart attack and circulatory collapse. Air conditioning systems made based on desiccants. Refrigerant poisoning results in Throat swelling, loss of vision, blood vomiting, blood in the stool, severe abdominal pain and even death is possible. This can be overcome by using air cycle cooling process instead of Freon as a phase changing material. Air Cycle Machine is the system used in aircraft cabin pressurization and cooling system which does not uses refrigerants in the cooling process. The analytical work carried out in this paper is to study the air conditioning system using Air Cycle Machine and investigate the air flow inside the room by giving the various inlet temperatures and the inlet velocity of the Air-conditioner. ANSYS-FLUENT 16.0 is used for the analytical study. A cabin enclosure was modeled and analyzed for different inlet temperatures and velocities and out coming cool air spread nature for the given conditions have been observed. The qualitative results of this study clearly evident the usage of Air Cycle Machine (ACM) is prominently reduces the room temperature than the refrigerant system and spreads the cool air throughout the enclosed room makes a comfortable environment and this would not leads to any health hazards. Thus this study is certain to use Air Cycle Machine (ACM) for the cabin cooling system rather than refrigerants.


2013 ◽  
Vol 21 (02) ◽  
pp. 1350012 ◽  
Author(s):  
AKIRA KANEKO ◽  
MASAFUMI KATSUTA ◽  
YUKI HAMANO

For an automobile air-conditioning system, performance improvement of the heat exchanger is needed to fit in the change of refrigerant and heat pump system. In this study, the heat transfer and pressure drop characteristic of air flow between parallel plates with concavity and convexity is grasped, and the possibility of using a fin-less heat exchanger is considered analytically. And it has been shown that a fin-less heat exchanger has the possibility of increasing performance compared to a conventional heat exchanger, which uses a corrugated louver fin.


2009 ◽  
Vol 13 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Sivakumar Kalaiselvam ◽  
Ragupathy Saravanan

The rise in crisis of power enthralls the world economically and the options for conventional and non-conventional energy resources have been searched out. No system exists in this world with 100% efficiency due to several irreversibility's. If the output obtained from the system is maximum for a given input, maximum amount of energy can be saved globally. To understand the thermodynamic losses occurring in the system and to predict the available energy that can be tapped from the system, exergy plays a major role. Experimental study on exergy in a system can pave the way to understand the complete behavior of the system exergually. Conceptually exergy studies are based on simulation, to provide a new dimension to the concept of exergy experimental validation have been promoted. The analogy of exergy analysis of three refrigerants working in scroll compressors and their exergual features are explained in this paper. The refrigerants R22, R417A, and R407C and their thermo dynamical behavior, irreversibility were experimented in an air conditioning system with three scroll compressors, interaction between the system and the refrigerant in terms of pressure drop and heat transfer, friction has been implemented for the calculation of exergy. The entire system performance on the basis of refrigerant is validated in each part of the air conditioning system. The resultant coefficient of performance of R407C is 2.41% less than R22 in a R22 designed scroll compressor with minimal exergy losses. The second law efficiency of 50 to 55% obtained in R22 has fewer rules over R407C and R417A which has 48 to 52%. The diminutive deviation of results encourages R417A refrigerant to be used as a substitute for R22. Thus the exergual prediction of performance of refrigerant and second law efficiency can identify the use of eco-friendly refrigerant in scroll compressor.


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