scholarly journals Exergy Analysis of Two Kinds of Solar-Driven Cogeneration Systems in Lhasa, Tibet, China

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Haofei Zhang ◽  
Bo Lei ◽  
Tao Yu ◽  
Zhida Zhao
Keyword(s):  
Solar Collector ◽  
Exergy Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Solar Collectors ◽  
Heating Water ◽  
Different Temperatures ◽  
Parallel Mode ◽  
Evacuated Tube Collectors ◽  
Evacuated Tube

In this study, an exergy analysis of two kinds of solar-driven cogeneration systems consisting of solar collectors and an organic Rankine cycle (ORC) is presented for series mode and parallel mode. Three kinds of solar collectors are considered: flat-plate collectors (FPC), evacuated tube collectors (ETC), and parabolic trough collectors (PTC). This study mainly compares the exergy output of the two kinds of solar cogeneration systems under different temperatures of the return heating water and different inlet temperatures of the solar collectors. This study shows that, from the perspective of Wnet or E̲n, the parallel mode is superior to the series mode. From the perspective of Ez, the parallel mode is superior to the series mode when the solar collector is FPC; however, the series mode is superior to the parallel mode when the solar collector is PTC. When the solar collector is ETC, the result depends on the temperature of the return heating water. When the temperature of the return heating water is low (below 46°C), the series mode is better, and when the temperature of the return heating water is high (above 46°C), the parallel mode is better.

scholarly journals Form and Operation Mode Analysis of a Novel Solar-Driven Cogeneration System with Various Collector Types

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Haofei Zhang ◽  
Bo Lei ◽  
Tao Yu ◽  
Zhida Zhao
Keyword(s):  
Operation Mode ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Mode Analysis ◽  
Solar Collectors ◽  
Operating Modes ◽  
Operation Modes ◽  
Cogeneration System ◽  
Heating Load ◽  
Evacuated Tube Collectors

In this study, the form and operation modes of a novel solar-driven cogeneration system consisted of various solar collectors (flat plat collectors (FPC), evacuated tube collectors (ETC), and parabolic trough collectors (PTC)) and ORC (organic Rankine cycle) based on building heating load are analyzed. This paper mainly obtains the fitting formula of thermal efficiency of the ORC power generation device and determines the form and operation mode of the cogeneration system. The form is the same, but the operation modes are different for PTC and FPC or ETC. There are six operating modes, respectively, based on the size relationship between the heating load of buildings and the effective heat collection of the solar collector subsystem when the solar collectors are PTC or FPC and ETC.

Parametric Study of a Flat Plate Wick Assisted Heat Pipe Solar Collector

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Brahim Taoufik ◽  
Mhiri Foued ◽  
Jemni Abdelmajid
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Solar Collector ◽  
Solar Collectors ◽  
Absorber Plate ◽  
Steady State Condition ◽  
Collector Efficiency ◽  
Evacuated Tube Collectors ◽  
Gap Spacing ◽  
Evacuated Tube

The use of heat pipes in solar collectors offers several advantages regarding flexibility in operation and application, as they are very efficient in transporting heat even under a small temperature difference. Compared with other systems powered by evacuated tube collectors or flat plate solar collectors using a wickless heat pipe, little attention has been paid to a flat plate solar collectors wick assisted heat pipe. In this paper an analytical model based on energy balance equations assuming a steady state condition was developed to evaluate the thermal efficiency of a flat plate wick assisted heat pipe solar collector. Parameters which affect the collector efficiency are identified, such as tube spacing distance, gap spacing between the absorber plate and the glazing cover, and the emissivity of the absorber plate. The results reflect the contribution and significance of each of these parameters to the collector overall heat loss coefficients. Three heat pipe working fluids are examined and results show that acetone performs better than methanol and ethanol.

EXERGY ANALYSIS OF A TRIGENERATION SYSTEM INTEGRATED WITH ORGANIC RANKINE CYCLE USING FRESNEL TECNOLOGY

2016 ◽  
Author(s):  
Flávio Pacelli Ziviani de Oliveira ◽  
Henrique Neiva Guimarães ◽  
Breno Gusmão Barbosa
Keyword(s):  
Exergy Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle

Exergy Analysis of a Combined Gas Turbine and Organic Rankine Cycle Based Power and Absorption Cooling Systems

2019 ◽  
Author(s):  
Joy Nondy ◽  
Tapan Kr. Gogoi
Keyword(s):  
Gas Turbine ◽  
Exergy Analysis ◽  
Cooling System ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Energy Output ◽  
Steam Turbines ◽  
Cooling Systems ◽  
Economic Point ◽  
Absorption Cooling

Abstract In this paper, a combined power and cooling system is thermodynamically analyzed. The system consists of a natural gas-fired gas turbine (GT) plant integrated with a heat recovery steam generator (HRSG), two steam turbines (STs), one organic Rankine cycle (ORC) and two absorption cooling systems (ACSs). With certain given input parameters, the GT plant produces net power of 36.06 MW, the two STs contribute 17.07 MW while from the ORC, 7.18 MW of net power was obtained. From the steam-operated ACS-I, a net 10.36 MW of cooing could be produced. Again, from the GT exhaust operated ACS-II, it was possible to generate additional 3.37 MW of cooling. From exergy analysis, it was found that the total irreversibility was the highest in the GT cycle with a net contribution of 180.412 MW followed by 4.178 MW from the HRSG, 3.561 MW from the ORC, 1.743 MW from ACS-I, 1.186 MW from ST-I, 0.812 MW from ACS-II, 0.175 MW from ST-II. The exergy efficiencies of the GT cycle, ORC, ACS-I and ACS-II were found 22.00%, 65.48%, 18.95% and 14.4% respectively. Regarding the power and cooling output, it can be concluded that these results are specific to the selected operating parameters. Further investigation is required, where, other similar configurations may be considered to make a final comment on the suitability of the proposed configuration from energy output and economic point of view.

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