Performance Enhancement of Window-Type Air-Conditioning Units

2018 ◽  
Vol 26 (02) ◽  
pp. 1850012 ◽  
Author(s):  
Ali K. Shaker Al-Sayyab

In this work, the performance of window-type air-conditioning units was improved. The study was achieved by adding a diffuser at the compressor outlet. An experimental investigation was carried out on 2 RT window-type air-conditioning units with controlled environmental zones. According to the compressor-outlet conditions, an ANSYS-fluent program was used to achieve a suitable diffuser geometry for maximum pressure increase. The refrigeration cycle model was programmed in Engineering Equation Solver (EES). The experimental work shows that using a diffuser of (5[Formula: see text]mm ID [Formula: see text] 9[Formula: see text]mm OD [Formula: see text] 12[Formula: see text]mm L) in an air-conditioning system will decrease the required compressor pressure ratio by 6% from the base case with an overall pressure increase of 1.4 bar and a 29% COP increase from the base case[Formula: see text]

2020 ◽  
Vol 28 (04) ◽  
pp. 2050031
Author(s):  
Ali K. Shaker Al-Sayyab

In this study, the performance of a window-type air-conditioning unit with an alternative, ozone-friendly refrigerant was enhanced by incorporating a nozzle instead of a capillary tube as an expansion device. An experimental evaluation was adopted on a 1.5 RT window-type air-conditioning unit with a controlled environmental zone. According to operating conditions, an ANSYS-Fluent program was used to predict an appropriate nozzle size for a lower pressure ratio. The refrigeration cycle model was simulated using the Engineering Equation Solver (EES).27 The results showed that using a nozzle of 30[Formula: see text]mm length and inner and outer diameters of 9 and 2[Formula: see text]mm, respectively instead of the capillary tube with R404A reduces compressor power consumption by 7.7% and increases the coefficient of performance (COP) by 7.4%.


2009 ◽  
Vol 50 (12) ◽  
pp. 2992-2998 ◽  
Author(s):  
Ming-Jer Hsiao ◽  
Chiao-Hung Cheng ◽  
Ming-Chao Huang ◽  
Sih-Li Chen

1999 ◽  
Author(s):  
Craig W. Wood ◽  
Josua P. Meyer

Abstract This study involves the experimental verification of a universal heat exchanger accumulator design procedure. A heat exchange accumulator was manufactured according to a mathematical model developed by the authors and installed into a small air conditioning system. Experimental results show that the addition of the heat exchanger accumulator results in a liquid overfeeding operation that replaces the previously utilized direct expansion operation. It provides an improved air conditioning system that has a 7.5% increase in coefficient of performance and a 4.4% increase in refrigerant mass flow rate. A pressure ratio reduction has a positive effect on the compressor performance and life span. Liquid overfeeding increases the cooling capacity of the system by 6.5%. When compared to direct expansion systems, this basic heat exchanger accumulator provides a reduction in cycling losses and power consumption, an increase in suction pressure and an improvement in isentropic compressor efficiency.


2018 ◽  
Vol 35 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Antonios Fatsis

Abstract Wave rotors are rotating equipment designed to exchange energy between high and low enthalpy fluids by means of unsteady pressure waves. In turbomachinery, they can be used as topping devices to gas turbines aiming to improve performance. The integration of a wave rotor into a ground power unit is far more attractive than into an aeronautical application, since it is not accompanied by any inconvenience concerning the over-weight and extra dimensioning. Two are the most common types of ground industrial gas turbines: The one-shaft and the two-shaft engines. Cycle analysis for both types of gas turbine engines topped with a four-port wave rotor is calculated and their performance is compared to the performance of the baseline engine accordingly. It is concluded that important benefits are obtained in terms of specific work and specific fuel consumption, especially compared to baseline engines with low compressor pressure ratio and low turbine inlet temperature.


Author(s):  
Pezhman Akbari ◽  
Norbert Mu¨ller

Results are presented predicting the significant performance enhancement of two small gas turbines (30 kW and 60 kW) by implementing various wave rotor topping cycles. Five different advantageous implementation cases for a four-port wave rotor into given baseline engines are considered. The compressor and turbine pressure ratios, and the turbine inlet temperatures vary in the thermodynamic calculations, according to the anticipated design objectives of the five cases. Advantages and disadvantages are outlined. Comparison between the theoretic performance (expressed by specific cycle work and overall thermal efficiency) of wave-rotor-topped and baseline engines shows a performance enhancement by up to 33%. The results obtained show that almost all the cases studied benefit from the wave-rotor-topping, but the highest gain is obtained for the case in which the topped engine operates with the same turbine inlet temperature and compressor pressure ratio as the baseline engine. General design maps are generated for the small gas turbines, showing the design space and optima for baseline and topped engines.


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