Experimental investigation of the loop thermosyphon with different adiabatic lengths charged with different working fluids

Heat Transfer ◽  
2021 ◽  
Author(s):  
Mahasidha R. Birajdar ◽  
C. M. Sewatkar
Keyword(s):  
Experimental Investigation ◽  
Working Fluids

The Experimental Investigation and Theoretical Analysis on Transcritical Carbon Dioxide Heat Pump Cycle

2012 ◽  
Vol 455-456 ◽  
pp. 240-245
Author(s):  
Lu Xiang Zong ◽  
Jian Lin Liu ◽  
Xue Shi ◽  
Ying Bai Xie
Keyword(s):  
Carbon Dioxide ◽  
Experimental Investigation ◽  
Theoretical Analysis ◽  
Heat Pump ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Working Fluids ◽  
Heat Pump System ◽  
Exit Temperature ◽  
Transcritical Carbon Dioxide

The (H)CFC-phase out and the fear for future problems for other synthetic working fluids, because of their known and unknown impact on the environment, have introduced a rising interest in environmentally safe natural working fluids. CO2is one of the few non-toxic and non-flammable working fluids that do not contribute to ozone depletion or global warming, if leaked to the atmosphere. Because the critical temperature of CO2is only 31.1°C, the transcritical cycle can be used to improve the coefficient of performance of the system. The experimental investigation and theoretical analysis on transcritical carbon dioxide heat pump system are carried out in this paper. It points out that there is an optimum operational pressure on transcritical carbon dioxide heat pump cycle, when the outlet temperature of gas cooler is constant, the coefficient of performance increases with increasing evaporating temperature at the same conditions, and the operational efficiency increased with decrease of gas cooler exit temperature. So in order to obtain the optimum performance, the influence of evaporating temperature, gas cooler exit temperature, and the operational pressure should be considered during the designing and operating transcritical carbon dioxide heat pump system.

scholarly journals Experimental investigation of modern ORC working fluids R1224yd(Z) and R1233zd(E) as replacements for R245fa

2019 ◽  
Vol 240 ◽  
pp. 946-963 ◽  
Author(s):  
Sebastian Eyerer ◽  
Fabian Dawo ◽  
Johannes Kaindl ◽  
Christoph Wieland ◽  
Hartmut Spliethoff
Keyword(s):  
Experimental Investigation ◽  
Working Fluids

Experimental Study of Methane Fuel Oxycombustion in an SI Engine

2012 ◽  
Author(s):  
Andrew Van Blarigan ◽  
Darko Kozarac ◽  
Reinhard Seiser ◽  
Robert Cattolica ◽  
Jyh-Yuan Chen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Combustion Efficiency ◽  
Working Fluid ◽  
Si Engine ◽  
Lower Efficiency ◽  
Working Fluids ◽  
Spark Timing

An experimental investigation of the thermal efficiency, combustion efficiency, and CoV IMEP, of methane fuel oxycombustion in an SI engine has been carried out. Compression ratio, spark-timing, and oxygen concentration were all varied. A variable compression ratio SI engine was operated on both wet and dry EGR working fluids, with results illustrating that the efficiency of the engine operating with a large amount of EGR was significantly reduced relative to methane-in-air operation over all oxygen concentrations and compression ratios. The maximum thermal efficiency of wet EGR, dry EGR, and air was found to be 23.6%, 24.2%, and 31.4%, respectively, corresponding to oxygen volume fractions of 29.3%, 32.7% and 21%. Combustion efficiency was above 98% for wet EGR and approximately 96% for dry EGR. CoV IMEP was low for both cases. The much lower efficiency of both EGR cases relative to air is primarily a result of the reduced specific-heat ratio of the EGR working fluids relative to air working fluid.

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