Performance of Ejector Refrigeration Cycle for Automotive Air Conditioning

2016 ◽  
Vol 819 ◽  
pp. 202-206
Author(s):  
Reza Maziar ◽  
Kasni Sumeru ◽  
M.Y. Senawi ◽  
Farid Nasir Ani
Keyword(s):  
Compression Ratio ◽  
Air Conditioning ◽  
The Other ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Entrainment Ratio ◽  
Automotive Air Conditioning ◽  
Average Improvement

In this study, two experiments were performed, one with the conventional compression refrigeration cycle (CRC) and the other with an ejector refrigeration cycle (ERC). The CRC system for automotive air conditioning was designed, fabricated and experiments were conducted. The system was then retrofitted with an ejector as the expansion device and experiments were repeated for the ERC system. Calculations of the entrainment ratio, compressor compression ratio and coefficient of performance (COP) were made for each cycle. The calculations showed that ERC has some advantages over the CRC. In this study, an average improvement of 5% in COP has been obtained for the ERC compared with the CRC.

scholarly journals Parametric analysis of a combined ejector-vapor compression refrigeration cycle

2020 ◽  
Vol 15 (3) ◽  
pp. 398-408
Author(s):  
I Ouelhazi ◽  
Y Ezzaalouni ◽  
L Kairouani
Keyword(s):  
Current Model ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Constant Area ◽  
Vapor Compression Refrigeration Cycle ◽  
Vapor Compression Refrigeration

Abstract From the last few years, the use of efficient ejector in refrigeration systems has been paid a lot of attention. In this article a description of a refrigeration system that combines a basic vapor compression refrigeration cycle with an ejector cooling cycle is presented. A one-dimensional mathematical model is developed using the flow governing thermodynamic equations based on a constant area ejector flow model. The model includes effects of friction at the constant-area mixing chamber. The current model is based on the NIST-REFPROP database for refrigerant property calculations. The model has basically been used to determine the effect of the ejector geometry and operating conditions on the performance of the whole refrigeration system. The results show that the proposed model predicts ejector performance, entrainment ratio and the coefficient of performance of the system and their sensitivity to evaporating and generating temperature of the cascade refrigeration cycle. The simulated performance has been then compared with the available experimental data from the literature for validation.

scholarly journals Thermal Performance Analysis of Low-GWP Refrigerants in Automotive Air-Conditioning System

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yousuf Alhendal ◽  
Abdalla Gomaa ◽  
Gamal Bedair ◽  
Abdulrahim Kalendar
Keyword(s):  
Air Conditioning ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Exergy Destruction ◽  
Air Conditioning System ◽  
Capacity Coefficient ◽  
Automotive Air Conditioning ◽  
Automotive Air Conditioning System ◽  
Compressor Power ◽  
Low Global Warming Potential

The energy and exergy of low-global warming potential (GWP) refrigerants were investigated experimentally and theoretically. Refrigerants with a modest GWP100 of  ≤ 150 can be sufficient for bringing down emissions which were concerned for the automotive air-conditioning system. Three types of low-GWP refrigerants, R152a, R1234yf, and R1234ze(E), were examined with particular reference to the current high-GWP of R134a. The effect of different evaporating and condensing temperatures in addition to compressor speed was considered. The purpose was to bring a clear view of the performance characteristics of possible environment friendly alternatives of R134a. The analysis was carried out with compressor power, cooling capacity, coefficient of performance, exergy destruction, and exergy efficiency. It was noted that the total exergy destruction of R1234yf was reduced by 15% compared to that of R134a. The refrigerant R1234ze(E) has the highest energetic and exergetic performance compared with the other investigated refrigerants.

A Study on the Combined Driven Refrigeration Cycle Using Ejector

2021 ◽  
pp. 2150004
Author(s):  
Waseem Raza ◽  
Gwang Soo Ko ◽  
Youn Cheol Park
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Primary Source ◽  
Mechanical Efficiency ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Working Fluid ◽  
Low Grade ◽  
Refrigeration Cycle ◽  
R 134A

The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4[Formula: see text]mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.

scholarly journals Exergy and Exergoeconomic Analysis of a Cogeneration Hybrid Solar Organic Rankine Cycle with Ejector

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 702
Author(s):  
Bourhan Tashtoush ◽  
Tatiana Morosuk ◽  
Jigar Chudasama
Keyword(s):  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Temperature And Pressure

Solar energy is utilized in a combined ejector refrigeration system with an organic Rankine cycle (ORC) to produce a cooling effect and generate electrical power. This study aims at increasing the utilized share of the collected solar thermal energy by inserting an ORC into the system. As the ejector refrigeration cycle reaches its maximum coefficient of performance (COP), the ORC starts working and generating electrical power. This electricity is used to run the circulating pumps and the control system, which makes the system autonomous. For the ejector refrigeration system, R134a refrigerant is selected as the working fluid for its performance characteristics and environmentally friendly nature. The COP of 0.53 was obtained for the ejector refrigeration cycle. The combined cycle of the solar ejector refrigeration and ORC is modeled in EBSILON Professional. Different parameters like generator temperature and pressure, condenser temperature and pressure, and entrainment ratio are studied, and the effect of these parameters on the cycle COP is investigated. Exergy, economic, and exergoeconomic analyses of the hybrid system are carried out to identify the thermodynamic and cost inefficiencies present in various components of the system.

Performance Analysis and Simulation of Automotive Air Conditioning Systems

2012 ◽  
Vol 260-261 ◽  
pp. 357-361
Author(s):  
Zhi Zhang ◽  
Peng Du ◽  
Pei Zhang
Keyword(s):  
Simulation Model ◽  
Air Conditioning ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Cycle System ◽  
Air Inlet ◽  
Automotive Air Conditioning ◽  
Air Conditioning Systems ◽  
The Mathematical Model ◽  
Performance Analysis And Simulation

This paper analyzes the automotive air conditioning refrigeration cycle system, to establish the mathematical model of the compressor, condenser and evaporator. Using the Matlab to build a simulation model of the automotive air conditioning and refrigeration systems. by the simulation model of automobile air conditioning compressor, condenser and evaporator match the condensing temperature, evaporating temperature, air inlet temperature ,it is shown this model is reasonable

Second law optimization of two-stage transcritical CO2 refrigeration cycles in the cooling mode operation

2009 ◽  
Vol 223 (5) ◽  
pp. 551-561 ◽  
Author(s):  
M Yari
Keyword(s):  
Geometric Mean ◽  
Internal Heat ◽  
Coefficient Of Performance ◽  
Second Law ◽  
Refrigeration Cycle ◽  
Cooling Mode ◽  
Two Stage ◽  
Entrainment Ratio ◽  
Cycle Simulation ◽  
Mean Pressure

Second law optimization studies of two-stage transcritical CO2 (TRCC) refrigeration cycles, incorporating options such as a new ejector-expansion with internal heat exchanger (IHE) and intercooler (IC), flash gas bypass, flash gas intercooling, compressor intercooling with IHE, are presented based on cycle simulation. To validate the simulations, the available numerical data in open literature are used. It is found that the coefficient of performance (COP) and second law efficiency of the new two-stage TRCC cycle are on average 16.5, 18.4, and 28.4 per cent higher than that of the two-stage TRCC with IHE and IC, the two-stage TRCC with flash gas bypass, and the two-stage TRCC with flash gas intercooling cycles, respectively. Hence, the new two-stage refrigeration cycle is a promising refrigeration cycle from the thermodynamic point of view. It is also concluded that for cases of the flash gas bypass and flash gas intercooling the optimum inter-stage pressure deviates significantly from the geometric mean pressure of the gas cooler and evaporator pressure. While for the new two-stage TRCC and the two-stage TRCC with IHE and IC, the optimum inter-stage pressure is approximately equal to geometric mean pressure. Finally, a regression analysis was employed in terms of evaporator and gas cooler exit temperatures to develop mathematical expressions for maximum COP, optimum discharge, and inter-stage pressures and entrainment ratio.

scholarly journals EFFECT OF AIR FLOW OBSTRUCTION IN A CONDENSING UNIT ON SPLIT AIR CONDITIONER PERFORMANCE

2020 ◽  
Vol 82 (5) ◽  
Author(s):  
Andriyanto Setyawan
Keyword(s):  
Air Conditioning ◽  
Air Flow ◽  
Cooling Capacity ◽  
Input Power ◽  
The Other ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
Heat Rejection ◽  
Other Hand

Obstructions of air flow in the outdoor unit could block the condenser air flow and reduce its heat rejection As a result, it could decrease the performance of a room air conditioning system. The paper presents the effects of the air flow obstruction of a condensing unit on the performance of a split-type air conditioner with refrigerant R410A. The study was conducted experimentally by employing front and side obstructions with varied distance from the condensing unit. The front obstruction of 100 cm height was applied at varied distance from 10 cm to 100 cm, while the side obstruction of the same height was applied at distance of 5, 10, and 15 cm. The presence of air flow obstructions results in the decrease of cooling capacity and coefficient of performance (COP). On the other hand, it increases the input power of the AC unit. From the experiment, it is obvious that the distance of front obstruction of 10 cm results in the reduction of cooling capacity by 46% and COP by 56%. It is also revealed that the distance of the front obstruction of 50 cm or more has no significant effect for the performance of the air conditioning unit. In addition, the side obstructions have the less significant effect than that of the front obstruction.

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